U.S. patent application number 14/423566 was filed with the patent office on 2015-08-27 for anti-smudge body, display device, input device, electronic device, and anti-smudge article.
The applicant listed for this patent is DEXERIALS CORPORATION. Invention is credited to Ryosuke Iwata, Mikihisa Mizuno.
Application Number | 20150240086 14/423566 |
Document ID | / |
Family ID | 50183441 |
Filed Date | 2015-08-27 |
United States Patent
Application |
20150240086 |
Kind Code |
A1 |
Iwata; Ryosuke ; et
al. |
August 27, 2015 |
ANTI-SMUDGE BODY, DISPLAY DEVICE, INPUT DEVICE, ELECTRONIC DEVICE,
AND ANTI-SMUDGE ARTICLE
Abstract
An anti-smudge body having a surface that, when fingerprints
adhere to the surface, allows the fingerprint patterns to spread
spontaneously to thereby cause them to become less noticeable has
the surface and a plurality of protrusions provided thereto. The
protrusions contain at least one of a first compound having an
ester linkage in a portion other than terminal ends and a second
compound having a cyclic hydrocarbon group.
Inventors: |
Iwata; Ryosuke;
(Utsunomiya-shi, JP) ; Mizuno; Mikihisa;
(Sendai-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DEXERIALS CORPORATION |
Tokyo |
|
JP |
|
|
Family ID: |
50183441 |
Appl. No.: |
14/423566 |
Filed: |
August 27, 2013 |
PCT Filed: |
August 27, 2013 |
PCT NO: |
PCT/JP2013/072798 |
371 Date: |
February 24, 2015 |
Current U.S.
Class: |
428/141 |
Current CPC
Class: |
B32B 2457/00 20130101;
B32B 2457/20 20130101; G02B 1/18 20150115; C09D 5/00 20130101; C09D
5/1668 20130101; G06F 1/1643 20130101; B32B 3/30 20130101; G06F
3/041 20130101; B32B 27/06 20130101; C09D 5/1687 20130101; C09D
5/1681 20130101; G02B 27/0006 20130101; Y10T 428/24355
20150115 |
International
Class: |
C09D 5/16 20060101
C09D005/16; G02B 27/00 20060101 G02B027/00; G06F 1/16 20060101
G06F001/16 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 31, 2012 |
JP |
2012-192272 |
Claims
1. An anti-smudge body comprising a surface and a plurality of
protrusions provided thereto, wherein the protrusions contain at
least one of a first compound having an ester linkage in a portion
other than terminal ends and a second compound having a cyclic
hydrocarbon group.
2. The anti-smudge body according to claim 1, wherein an average
height of the protrusions is in a range of 10 nm or larger and 150
nm or smaller, and an average pitch of the protrusions is in a
range of 100 nm or larger and 500 nm or smaller.
3. The anti-smudge body according to claim 2, wherein the average
height of the protrusions is in a range of 10 nm or larger and 100
nm or smaller.
4. The anti-smudge body according to claim 1, comprising a
substrate having a surface, and an anti-smudge layer provided on
the surface of the substrate, wherein the anti-smudge layer has a
surface on which the plurality of protrusions are disposed.
5. The anti-smudge body according to claim 4, wherein the
anti-smudge layer contains at least one resin composition of an
energy ray-curable resin composition and a thermosetting resin
composition, and the resin composition contains the at least one of
the first compound and the second compound.
6. The anti-smudge body according to claim 1, wherein the first
compound and the second compound are each an additive.
7. The anti-smudge body according to claim 6, wherein the additive
is a leveling agent.
8. The anti-smudge body according to claim 4, wherein a plurality
of protrusions are disposed on the surface of the substrate, and
the anti-smudge layer is provided so as to conform to the surface
of the plurality of protrusions of the substrate.
9. The anti-smudge body according to claim 8, wherein the at least
one of the first compound and the second compound is adsorbed onto
the surface of the plurality of protrusions of the substrate.
10. The anti-smudge body according to claim 9, wherein the
anti-smudge layer is a monomolecular layer containing the at least
one of the first compound and the second compound.
11. The anti-smudge body according to claim 1, wherein the
protrusions contain a thermoplastic resin composition, and the
thermoplastic resin composition contains the at least one of the
first compound and the second compound.
12. The anti-smudge body according to claim 1, wherein the first
compound is represented by the formula (1) or (2) below, and the
second compound is represented by the formula (3) or (4) below,
##STR00020## (wherein, in the formula (1), R.sub.1 is a group
containing C, N, S, O, Si, P, or Ti, and R.sub.2 is a group having
2 or more carbon atoms), ##STR00021## (wherein, in the formula (2),
R.sub.1 and R.sub.2 are each independently a group containing C, N,
S, O, Si, P, or Ti) ##STR00022##
13. The anti-smudge body according to claim 12, wherein R.sub.1 and
R.sub.2 in the formulas (1) and (2) above are each independently a
hydrocarbon group, a sulfo group, a sulfonyl group, a sulfonamide
group, a carboxylic acid group, an amino group, an amide group, a
phosphoric acid group, a phosphino group, a silanol group, an epoxy
group, an isocyanate group, a cyano group, a thiol group, or a
hydroxyl group.
14. The anti-smudge body according to claim 1, wherein the
anti-smudge layer further contains, together with the second
compound, a third compound having a chain hydrocarbon group at a
terminal end.
15. The anti-smudge body according to claim 14, wherein the third
compound is represented by the formula (5) or (6) below
##STR00023##
16. The anti-smudge body according to claim 1, wherein the
plurality of protrusions are arranged two-dimensionally.
17. The anti-smudge body according to claim 1, wherein a recessed
portion between the protrusions causes positive capillary pressure
to act on a liquid present on the surface.
18. An input device comprising an input surface and a plurality of
protrusions provided thereto, wherein the protrusions contain at
least one of a first compound having an ester linkage in a portion
other than terminal ends and a second compound having a cyclic
hydrocarbon group.
19. A display device comprising a display surface and a plurality
of protrusions provided thereto, wherein the protrusions contain at
least one of a first compound having an ester linkage in a portion
other than terminal ends and a second compound having a cyclic
hydrocarbon group.
20. An electronic device comprising a surface and a plurality of
protrusions provided thereto, wherein the protrusions contain at
least one of a first compound having an ester linkage in a portion
other than terminal ends and a second compound having a cyclic
hydrocarbon group.
21. An anti-smudge article comprising a surface and a plurality of
protrusions provided thereto, wherein the protrusions contain at
least one of a first compound having an ester linkage in a portion
other than terminal ends and a second compound having a cyclic
hydrocarbon group.
22. An anti-smudge body comprising an anti-smudge surface and a
plurality of protrusions provided thereto.
Description
TECHNICAL FIELD
[0001] The present technique relates to an anti-smudge body and to
a display device, an input device, an electronic device, and an
anti-smudge article each including the anti-smudge body.
Particularly, the present technique relates to an anti-smudge body
that suppresses smudges on a surface.
BACKGROUND ART
[0002] In recent years, information display devices equipped with a
touch panel as a user interface (UI) are rapidly becoming
widespread. A touch panel has an advantage in that the user can
operate the device intuitively by directly touching the display
screen with a finger. However, a problem with the touch panel is
that fingerprints adhering to the display screen deteriorate the
visibility of the display screen. Therefore, there is a demand for
a fingerprint resistant surface on which fingerprints adhering
thereto are less noticeable.
[0003] An anti-smudge layer designed such that a fluorine-based
compound or a silicon-based compound is present on the outermost
surface has been used for a display surface including a touch panel
(see, for example, Patent Literature 1). This is because the
outermost surface of the anti-smudge layer is a water-repellent and
oil-repellent surface, and has an effect in that the adhesion of
oil and fat components forming fingerprints is weakened, so that
the fingerprints can be easily wiped off with, for example, a
cloth.
[0004] Further, a water-repellent oleophilic surface that does not
repel oil and fat components has been proposed (see, for example,
Patent Literature 2). When fingerprints adhere to this surface, the
oil and fat components of fingerprints adhering to the surface
spread and do not form droplets, so that the fingerprints are less
noticeable.
CITATION LIST
Patent Literature
[0005] Patent Literature 1: Japanese Patent No. 4666667
[0006] Patent Literature 2: Japanese Patent Application Laid-Open
No. 2010-128363
SUMMARY OF INVENTION
Technical Problem
[0007] As described above, there is a demand for a surface that
allows fingerprints adhering thereto to become less noticeable. In
consideration of applications such as capacitive type touch panels,
a surface that allows fingerprint patterns to spread spontaneously
to thereby cause them to become less noticeable (a fingerprint
resistant surface) is considered to be important.
[0008] Accordingly, it is an object of the present technique to
provide an anti-smudge body having a surface that, when
fingerprints adhere to the surface, allows the fingerprint patterns
to spread spontaneously to thereby cause them to become less
noticeable and to provide a display device, an input device, an
electronic device, and an anti-smudge article each including the
anti-smudge body.
Solution to Problem
[0009] To solve the foregoing problem, a first technique is an
anti-smudge body having
[0010] a surface and a plurality of protrusions provided thereto,
wherein
[0011] the protrusions contain at least one of a first compound
having an ester linkage in a portion other than terminal ends and a
second compound having a cyclic hydrocarbon group.
[0012] A second technique is an input device having
[0013] an input surface and a plurality of protrusions provided
thereto, wherein
[0014] the protrusions contain at least one of a first compound
having an ester linkage in a portion other than terminal ends and a
second compound having a cyclic hydrocarbon group.
[0015] A third technique is a display device having
[0016] a display surface and a plurality of protrusions provided
thereto, wherein
[0017] the protrusions contain at least one of a first compound
having an ester linkage in a portion other than terminal ends and a
second compound having a cyclic hydrocarbon group.
[0018] A fourth technique is an electronic device having
[0019] a surface and a plurality of protrusions provided thereto,
wherein
[0020] the protrusions contain at least one of a first compound
having an ester linkage in a portion other than terminal ends and a
second compound having a cyclic hydrocarbon group.
[0021] A fifth technique is an anti-smudge article having
[0022] a surface and a plurality of protrusions provided thereto,
wherein
[0023] the protrusions contain at least one of a first compound
having an ester linkage in a portion other than terminal ends and a
second compound having a cyclic hydrocarbon group.
[0024] A sixth technique is an anti-smudge body having an
anti-smudge surface and a plurality of protrusions provided
thereto.
[0025] In the present technique, the anti-smudge body is preferably
an anti-smudge layer, an anti-smudge structure layer, or an
anti-smudge substrate. The anti-smudge structure layer means a
structure layer including a plurality of protrusions and an
anti-smudge layer provided so as to conform to the surface of the
protrusions.
[0026] In the present technique, the plurality of protrusions are
disposed on the surface of the anti-smudge body, and the
protrusions contain at least one of a first compound having an
ester linkage in a portion other than terminal ends and a second
compound having a cyclic hydrocarbon group. Therefore, when
fingerprints adhere to the surface, the fingerprint patterns spread
spontaneously and become less noticeable.
Advantageous Effects of Invention
[0027] As described above, with the present technique, when
fingerprints adhere to the surface of the anti-smudge body, the
fingerprint patterns spread spontaneously and become less
noticeable.
BRIEF DESCRIPTION OF DRAWINGS
[0028] FIG. 1A is a cross-sectional view illustrating an example of
a configuration of an anti-smudge substrate according to a first
embodiment of the present technique.
[0029] FIG. 1B is a plan view illustrating the example of the
configuration of the anti-smudge substrate according to the first
embodiment of the present technique.
[0030] FIG. 2A is a perspective view illustrating an example of a
configuration of a master roll. FIG. 2B is an enlarged plan view
illustrating part of the master roll shown in FIG. 2A. FIG. 2C is a
cross-sectional view in a track T in FIG. 2B.
[0031] FIG. 3 is a schematic diagram illustrating an example of a
configuration of a master roll exposure apparatus for producing the
master roll.
[0032] FIGS. 4A to 4C are process diagrams illustrating an example
of the method of producing the anti-smudge substrate according to
the first embodiment in the present technique.
[0033] FIGS. 5A and 5B are process diagrams illustrating an example
of the method of producing the anti-smudge substrate according to
the first embodiment in the present technique.
[0034] FIGS. 6A to 6C are process diagrams illustrating an example
of the structure forming step using an energy ray curable resin or
a thermosetting resin.
[0035] FIGS. 7A to 7C are process diagrams illustrating an example
of the structure forming step using a thermoplastic resin
composition.
[0036] FIG. 8A is a cross-sectional view illustrating an example of
a configuration of an anti-smudge substrate according to a first
modification. FIG. 8B is a cross-sectional view illustrating an
example of a configuration of an anti-smudge substrate according to
a second modification. FIG. 8C is a cross-sectional view
illustrating an example of a configuration of an anti-smudge
substrate according to a third modification.
[0037] FIG. 9A is a cross-sectional view illustrating an example of
a configuration of an anti-smudge substrate according to a fourth
modification. FIG. 9B is a cross-sectional view illustrating an
example of a configuration of an anti-smudge substrate according to
a fifth modification. FIG. 9C is a cross-sectional view
illustrating an example of a configuration of an anti-smudge
substrate according to a sixth modification.
[0038] FIG. 10 is a cross-sectional view illustrating an example of
a configuration of an anti-smudge substrate according to a second
embodiment of the present technique.
[0039] FIG. 11A is a cross-sectional view illustrating an example
of a configuration of an anti-smudge substrate according to a third
embodiment of the present technique.
[0040] FIG. 11B is an enlarged cross-sectional view representing
part of FIG. 11A.
[0041] FIG. 12A is a cross-sectional view illustrating a first
example of a configuration of an anti-smudge layer. FIG. 12B is a
cross-sectional view illustrating a second example of a
configuration of an anti-smudge layer. FIG. 12C is a
cross-sectional view illustrating a third example of a
configuration of an anti-smudge layer.
[0042] FIG. 13 is an exploded perspective view illustrating an
example of a configuration of a display device according to a
fourth embodiment of the present technique.
[0043] FIG. 14A is an exploded perspective view illustrating an
example of a configuration of an input device according to a fifth
embodiment of the present technique.
[0044] FIG. 14B is an exploded perspective view illustrating a
modification of an input device according to the fifth embodiment
of the present technique.
[0045] FIG. 15A is an external view illustrating a television set,
which is an example of the electronic device.
[0046] FIG. 15B is an external view illustrating a notebook-type
personal computer, which is an example of the electronic
device.
[0047] FIG. 16A is an external view illustrating a cellular phone,
which is an example of the electronic device. FIG. 16B is an
external view illustrating a tablet-type computer, which is an
example of the electronic device.
[0048] FIG. 17A is a view showing an AFM image of the surface of
the anti-smudge film in Example 1. FIG. 17B is a view illustrating
a cross-sectional profile along line a-a shown in FIG. 17A.
[0049] FIG. 18A is a view showing an AFM image of the surface of
the anti-smudge film in Example 2. FIG. 18B is a view illustrating
a cross-sectional profile along line a-a shown in FIG. 18A.
[0050] FIG. 19A is a view showing an AFM image of the surface of
the anti-smudge film in Example 8. FIG. 19B is a view illustrating
a cross-sectional profile along line a-a shown in FIG. 19A.
DESCRIPTION OF EMBODIMENTS
[0051] Embodiments of the present technique will be described in
the following order.
[0052] 1. First embodiment (an example of an anti-smudge substrate
having a fingerprint resistant surface)
[0053] 2. Second embodiment (an example of an anti-smudge substrate
having a fingerprint resistant surface)
[0054] 3. Third embodiment (an example of an anti-smudge substrate
having a fingerprint resistant surface)
[0055] 4. Fourth embodiment (an example of an anti-smudge substrate
having a fingerprint resistant surface)
[0056] 5. Fifth embodiment (an example of a display device having a
fingerprint resistant surface)
[0057] 6. Sixth embodiment (an example of an input device having a
fingerprint resistant surface)
[0058] 7. Seventh embodiment (an example of an electronic device
having a fingerprint resistant surface)
1. First Embodiment
[Configuration of Anti-Smudge Substrate]
[0059] FIG. 1A is a cross-sectional view illustrating an example of
a configuration of an anti-smudge substrate according to a first
embodiment of the present technique. The anti-smudge substrate
(anti-smudge body) has a fingerprint resistant surface (anti-smudge
surface) S having an anti-fingerprint function, as shown in FIG.
1A. This fingerprint resistant surface S has fine protrusion-like
structures thereon and contains a compound having a specific
molecular structure described later. Therefore, fingerprints
adhering to the fingerprint resistant surface S spread
spontaneously and are likely to become less noticeable. When the
height of the fine protrusion-like structures is set to a
prescribed value, good wipeability can be obtained.
[0060] The anti-smudge substrate includes a substrate 11 and an
anti-smudge layer 12 disposed on the surface of the substrate 11.
In the following description, the anti-smudge substrate including
the substrate 11 and the anti-smudge layer 12 will be described as
an example of the anti-smudge body. However, the anti-smudge body
is not limited to this example, and the anti-smudge layer 12 alone
may be used as the anti-smudge body.
[0061] The anti-smudge substrate according to the first embodiment
is suitably applied to the surface of a device that is touched with
a hand, a finger, etc. The surface of such a device is, for
example, at least one portion of a display surface, an input
surface, or the surface of a casing. It is also preferable that the
anti-smudge layer 12 be applied directly to the surface of the
device with no substrate 11. Specific examples of the device that
is touched with a hand, a finger, etc. may include display devices,
input devices, and electronic devices.
[0062] Examples of the display devices may include various display
devices such as a liquid crystal display, a CRT (cathode ray tube)
display, a plasma display panel (PDP), an electro luminescence (EL)
display, and a surface-conduction electron-emitter Display
(SED).
[0063] Examples of the input devices may include, but are not
limited to, touch panels, mice, and keyboards. Examples of the
touch panels may include, but are not limited to, touch panels
provided in television sets, personal computers, mobile devices
(such as smart phones and slate PCs), and photo frames.
[0064] The electronic device is preferably an electronic device
including at least one of a display device, an input device, a
casing, etc. Examples of such an electronic device may include, but
are not limited to, television sets, personal computers (PC),
mobile devices (such as smart phones and slate PCs), and photo
frames.
[0065] The objects to which the anti-smudge substrate or the
anti-smudge layer 12 is applied are not limited to the
above-described devices, and the anti-smudge substrate or the
anti-smudge layer 12 is preferably applicable to any object having
a surface touched with a hand or a finger. Examples of articles
(anti-smudge articles) other than the devices described above
include, but are not limited to, paper, plastic, glass, and metal
products (specifically, for example, photographs, photograph
stands, plastic cases, metal cases, glass windows, plastic windows,
picture frames, lenses, furniture, and electric appliances).
(Substrate)
[0066] The substrate 11 is, for example, a transparent inorganic
substrate or a transparent plastic substrate. The shape of the
substrate 11 used may be, for example, a film shape, a sheet shape,
plate shape, or a block shape. Examples of the material of the
inorganic substrate may include quartz, sapphire, and glass. Any
known macromolecular material can be used as the material of the
plastic substrate. Specific examples of the known macromolecular
material may include triacetylcellulose (TAC), polyester (TPEE),
polyethylene terephthalate (PET), polyethylene naphthalate (PEN),
polyimide (PI), polyamide (PA), aramid, polyethylene (PE),
polyacrylate, polyether sulfone, polysulfone, polypropylene (PP),
polystyrene, diacetylcellulose, polyvinyl chloride, acrylic resin
(PMMA), polycarbonate (PC), epoxy resin, urea resin, urethane
resin, melamine resin, phenol resin,
acrylonitrile-butadiene-styrene copolymers, cycloolefin polymers
(COP), cycloolefin copolymers (COC), PC/PMMA stacked body, and
rubber added PMMA. A design or a pattern may be printed or
vapor-deposited on the substrate. When the anti-smudge substrate is
used for an exterior application, the substrate 11 may not be
transparent. Examples of the material of the substrate 11 may
include stainless steel, magnesium alloys, aluminum, aluminum
alloys, titanium alloys, galvalume steel, and carbon fiber
reinforced plastics.
[0067] The substrate 11 may be processed into part of the exterior
or display of an electronic device etc. The surface shape of the
substrate 11 is not limited to a flat shape, and the substrate 11
may have an uneven surface, a polygonal surface, a curved surface,
or a combination thereof. Examples of the curved surface may
include a spherical surface, an elliptic surface, a parabolic
surface, and a free curved surface. The anti-smudge substrate may
be formed into the curved surface by, for example, an in-mold
molding process. The in-mold molding is a process in which the
anti-smudge substrate is placed in a mold and a resin such as a
plastic is injected to perform molding and surface decorating
simultaneously. Alternatively, the anti-smudge substrate itself may
be subjected to press working using a pressing die to form the
anti-smudge substrate into the above-described curved surface. In
any of the above molding processes, a protective film may be placed
on the anti-smudge layer of the anti-smudge substrate, in order to
protect the protrusions on the surface of the anti-smudge substrate
from being damaged. A prescribed structure may be provided on the
surface of the substrate 11 by, for example, UV transfer, thermal
transfer, pressure transfer, melt extrusion, etc.
(Anti-Smudge Layer)
[0068] The anti-smudge layer 12 includes a plurality of protrusions
12a on the fingerprint resistant surface S. The anti-smudge layer
12 may further include a base layer 12b between the substrate 11
and the plurality of protrusions 12a. The base layer 12b is a layer
formed integrally with the protrusions 12a on the bottom side of
the protrusions 12a and is formed from the same material as that of
the protrusions 12a. The anti-smudge layer 12 is a modified surface
layer containing at least one of a first compound having an ester
linkage in a portion other than its terminal ends and a second
compound having a cyclic hydrocarbon group. Since the anti-smudge
layer 12 contains at least one of the first compound and the second
compound, the ease of wiping off fingerprints can be improved. The
above terminal ends are terminal ends of the main and side chains.
The anti-smudge layer 12 is a coating layer formed by, for example,
a wet process or a dry process.
[0069] When the anti-smudge layer 12 contains the second compound,
it is preferable that the anti-smudge layer 12 further contain,
together with the second compound, a third compound having a chain
hydrocarbon group at its terminal end. In this case, the ease of
wiping off fingerprints can be further improved. The above terminal
end is a terminal end of any of the main and side chains. No
particular limitation is imposed on the contents of the second and
third compounds in the anti-smudge layer 12. However, since the
third compound has the property of gathering on the fingerprint
resistant surface S relatively easily, it is preferable that the
contents be selected in consideration of this property.
[0070] The anti-smudge layer 12 contains at least one selected from
the group consisting of energy ray-curable resin compositions,
thermosetting resin compositions, and thermoplastic resin
compositions. These resin compositions contain, for example, at
least one of the first compound and the second compound. When these
resin compositions contain the second compound, it is preferable
that they contain the third compound together with the second
compound.
[0071] If necessary, the anti-smudge layer 12 may further contain
additives such as a polymerization initiator, a light stabilizer,
an ultraviolet absorber, a catalyst, a coloring agent, an
antistatic agent, a lubricant, a leveling agent, an antifoaming
agent, a polymerization promoter, an antioxidant, a flame
retardant, an infrared absorber, a surfactant, a surface modifier,
a thixotropic agent, and a plasticizer. The anti-smudge layer 12
may further contain light-scattering particles such as an organic
resin filler that scatter light, in order to impart an AG
(Anti-Glare) function to the fingerprint resistant surface S. When
the AG function is imparted, the light-scattering particles may
protrude from the fingerprint resistant surface S of the
anti-smudge layer 12 or may be covered with, for example, a resin
contained in the anti-smudge layer 12. The light-scattering
particles may or may not be in contact with the substrate 11, which
is a lower layer. The average thickness of the anti-smudge layer 12
is within the range of, for example, a monomolecular thickness or
more and 1 mm or less, preferably a monomolecular thickness or more
and 100 .mu.m or less, and particularly preferably a monomolecular
thickness or more and 10 .mu.m or less.
[0072] The first compound and/or the second compound is, for
example, at least one of main and accessory components of the
material constituting the anti-smudge layer 12. When the
anti-smudge layer 12 is a layer formed by a wet process, the main
component is, for example, a base resin, and the accessory
component is, for example, an additive such as the leveling agent
described above. Preferably, the first, second and third compounds
are additives. This is because, for example, deterioration of
hardness of the base resin can be suppressed. When any of these
compounds is an additive as described above, it is preferable that
the additive be a leveling agent. When the first, second and third
compounds are additives such as a leveling agent, it is preferable
that the first, second, and third compounds be bonded to the base
resin through, for example, a polymerization reaction. This is
because the durability of the fingerprint resistant surface S can
be improved.
(Protrusions)
[0073] FIG. 1B is a plan view illustrating an example of an
arrangement of the plurality of protrusions disposed on the surface
of the substrate 11. As shown in FIG. 1B, the plurality of
protrusions 12a are arranged two-dimensionally on the surface of
the substrate 11. The arrangement may be any of a regular
arrangement and a random arrangement. However, when the anti-smudge
substrate is produced using a production method described later, a
regular arrangement is preferred.
[0074] The plurality of protrusions 12a have an arrangement pattern
in which a plurality of tracks T are formed on the surface of the
substrate 11. In the present technique, the tracks are rows of
protrusions 12a. The tracks T may have a linear shape, a circular
shape, or an arc shape, and the tracks T having any of these shapes
may be wobbled (meandered). Such wobbled tracks T can suppress the
occurrence of unevenness in appearance.
[0075] When the tracks T are wobbled, it is preferable that the
wobbles of the respective tracks T on the substrate 11 be
synchronized. Specifically, it is preferable that the wobbles are
synchronized wobbles. By synchronizing the wobbles, the shape of
unit cells Uc can be maintained, and a high filling factor can be
maintained. Examples of the waveform of the wobbled tracks T may
include sinusoidal waves and triangular shapes. The waveform of the
wobbled tracks T is not limited to a periodic waveform, and the
wobbled tracks T may have an aperiodic waveform. The amplitude of
the wobbles of the wobbled tracks T is selected to be, for example,
about .+-.10 nm.
[0076] The plurality of protrusions 12a arranged so as to form the
plurality of tracks T may form a regular periodic pattern. From the
viewpoint of improving the filling factor, it is preferable that
the plurality of protrusions 12a be arranged in a closest packed
structure with a regular periodic pattern. The regular periodic
pattern used may be a pattern including unit cells Uc. Examples of
the unit cells Uc may include lattice patterns such as
quadrilateral lattice patterns and hexagonal lattice patterns, and
these lattice patterns may be distorted. The height of the
protrusions 12a may be regularly or irregularly changed on the
surface of the substrate 11.
[0077] Examples of the shape of the protrusions 12a may include
cone shapes, columnar shapes, needle-like shapes, shapes formed of
part of a sphere (for example, hemispherical shapes), shapes formed
of part of an ellipsoid (for example, hemiellipsoidal shapes), and
polygonal shapes. However, the shape of the protrusions 12a is not
limited to these shapes, and any other shape may be used. Examples
of the cone shapes may include, but are not limited to, cone shapes
with sharp apexes, cone shapes with flat apexes (truncated cone
shapes), and cone shapes with convex or concave curved surfaces at
their apexes. Examples of the cone shapes with sharp apexes may
include a circular cone and polygonal pyramids. Examples of the
polygonal pyramids may include a triangular pyramid, a quadrangular
pyramid, a pentagonal pyramid, a hexagonal pyramid, and other
pyramids. Examples of the cone shapes with flat apexes (truncated
cone shapes) may include truncated circular cones and truncated
polygonal pyramids. Examples of the truncated polygonal pyramids
may include a truncated triangular pyramid, a truncated
quadrangular pyramid, a truncated pentagonal pyramid, a truncated
hexagonal pyramid, and other truncated pyramids. Examples of the
cone shapes with convex curved at their apexes may include quadric
surfaces such as: a cone shape in which its gradient is small at
the apex and increases gradually from the central portion toward
the bottom (a cone shape with a paraboloidal surface); and a cone
shape in which its gradient at the central portion is larger than
that at the bottom and the apex. The cone surface of a cone may be
curved convexly or concavely. Examples of the columnar shapes may
include cylinders and polygonal columns. Examples of the polygonal
columns may include quadrangular columns, pentagonal columns,
hexagonal columns, and other polygonal columns.
[0078] When a master roll is produced using a master roll exposure
apparatus (see FIG. 3) described later, it is preferable that the
shape of the protrusions 12a be an elliptic cone shape with a
convex curved surface at the apex or an elliptic cone shape with a
flat apex and that the major axis direction of the ellipse forming
their bottom surface coincide with the extending direction of the
tracks T. The circular, elliptic, circular cone, elliptic cone,
spherical, ellipsoidal, and parabolic shapes are meant to include
not only mathematically defined perfect circular, elliptic,
circular cone, elliptic cone, spherical, ellipsoidal, and parabolic
shapes but also somewhat distorted circular, elliptic, circular
cone, elliptic cone, spherical, ellipsoidal, and parabolic
shapes.
[0079] In FIGS. 1A and 1B, the protrusions 12a have the same size,
shape, arrangement pitch, height, and aspect ratio. However, the
configuration of the protrusions 12a is not limited thereto, and
protrusions 12a with at least two different sizes, shapes,
arrangement pitches, heights, and aspect ratios may be provided on
the surface of the substrate. The aspect ratio of a protrusion 12a
means the ratio of the height of the protrusion 12a to its
arrangement pitch P (H/P). The arrangement pitches P of protrusions
12a, their heights H and/or their aspect ratios (H/P) may be
different in different in-plane directions on the surface of the
substrate. No particular limitation is imposed on the positional
relation between adjacent protrusions 12a, and adjacent protrusions
12a may be configured so as to be spaced apart from each other, be
in contact with each other, or partially overlap each other.
[0080] The protrusions 12a may be formed so as to have a prescribed
height distribution. The height distribution means that protrusions
12a with at least two different heights are provided on the surface
of the substrate 11. For example, protrusions 12a having a
reference height and protrusions 12a having a height different from
the height of the above protrusions 12a may be provided on the
surface of the substrate 11. In this case, the protrusions 12a
having a height different from the reference height may be, for
example, disposed periodically or aperiodically (randomly) on the
surface of the substrate 11. The direction of the periodicity may
be, for example, the extending direction of the tracks T or a
direction at a prescribed angle from the tracks T (an inter-track
direction).
[0081] The average arrangement pitch Pm of the protrusions 12a is
preferably in the range of 1 nm or larger and 1 mm or smaller, more
preferably in the range of 10 nm or larger and 1 .mu.m or smaller,
and still more preferably in the range of 100 nm or larger and 500
nm or smaller. When the average arrangement pitch Pm is 1 nm or
larger and 1 mm or smaller, fingerprint patterns spread
effectively. The pitches of the protrusions 12a may not be
uniform.
[0082] The average height H of the protrusions 12a is preferably in
the range of 1 nm or larger and 1 mm or smaller, more preferably in
the range of 5 nm or larger and 300 nm or smaller, still more
preferably in the range of 10 nm or larger and 150 nm or smaller,
and most preferably in the range of 10 nm or larger and 100 nm or
smaller. When the average height H is 1 nm or larger and 1 mm or
smaller, fingerprint patterns spread effectively. When the average
height H is 100 nm or smaller, fingerprints adhering to the
fingerprint resistant surface S of the anti-smudge substrate can be
made less noticeable by rubbing the fingerprints with, for example,
a finger to spread them thinly. Therefore, the ease of wiping off
fingerprints with a finger etc. can be improved. The heights of the
protrusions 12a may not be uniform.
[0083] The average aspect ratio (the average height Hm/the average
arrangement pitch Pm) of the protrusions 12a is preferably in the
range of 0.000001 or larger and 1,000,000 or smaller, more
preferably in the range of 0.005 or larger and 300 or smaller, and
still more preferably in the range of 0.02 or larger and 1 or
smaller. When the average aspect ratio (the average height Hm/the
average arrangement pitch Pm) is 0.000001 or larger and 1,000,000
or smaller, fingerprint patterns spread effectively.
[0084] The average arrangement pitch Pm, average height Hm, and
average aspect ratio (Hm/Pm) of the protrusions 12a are determined
as follows.
[0085] First, the fingerprint resistant surface S having the
protrusions 12a is observed under an atomic force microscope (AFM),
and pitches and heights of protrusions 12a are determined from an
AFM cross sectional profile. This procedure is repeated for 10
regions randomly selected on the fingerprint resistant surface S to
determine arrangement pitches P1, P2, . . . , P10 and heights H1,
H2, . . . , H10. The pitch of protrusions 12a is the distance
between the apexes of these protrusions 12a, and the heights of the
protrusions 12a are their heights with reference to the lowest
point in recessed portions (valley portions) between the
protrusions. Then the pitches P1, P2, . . . , P10 and the heights
H1, H2, . . . , H10 are simply averaged (arithmetically averaged)
to determine the average arrangement pitch Pm and average height Hm
of the protrusions 12a. Next, the average aspect ratio Hm/Pm is
determined from the determined average arrangement pitch Pm and
average height Hm. When the pitches of the protrusions 12a are
in-plane anisotropic, the average arrangement pitch Pm is
determined using arrangement pitches in a direction in which the
arrangement pitches are maximum. When the heights of the
protrusions 12a are in-plane anisotropic, the average height Hm is
determined using heights in a direction in which the heights are
maximum.
[0086] The reflectance (5.degree. reflectance) of the anti-smudge
substrate on the fingerprint resistant surface S side is preferably
in the range of 1% or higher and 10% or lower. When the reflectance
is 1% or higher, fingerprint patterns are less noticeable in
fingerprint-adhering regions and non-adhering regions.
[0087] The reflectance is determined as follows.
[0088] First, treatment for cutting reflection from the rear
surface of the anti-smudge substrate (the surface opposite to the
side on which the protrusions 12a are formed) is performed by
applying a black tape to the rear surface of the anti-smudge
substrate. Next, the reflectance is measured using an ultraviolet
and visible spectrophotometer (product name: V-500, manufactured by
JASCO Corporation). For the measurement, a regular reflection
5.degree. unit is used. The above reflectance is a reflectance at a
wavelength of 550 nm.
[0089] When liquid is present on the fingerprint resistant surface
S, it is preferable that the recessed portions between the
protrusions 12a cause positive capillary pressure to act on the
liquid. When positive capillary pressure acts on a liquid droplet
present on the fingerprint resistant surface S, the liquid droplet
can be allowed to spread thinly. It is preferable to allow
capillary pressure in a depth direction to act on the liquid
droplet in addition to the positive capillary pressure. This is
because the liquid droplet can be allowed to spread more thinly.
Capillary pressure acting in a direction away from the liquid
droplet on the fingerprint resistant surface S is defined as the
positive capillary pressure.
(First Compound)
[0090] The first compound may be an organic material, an
organic-inorganic composite material, a macromolecular material, or
a monomolecular material, so long as the first compound has an
ester linkage in a portion other than terminal ends. No particular
limitation is imposed on the molecular structure of the first
compound so long as it has an ester linkage, and the first compound
may have any functional group, any bonding site, any hetero atom,
any halogen atom, any metal atom, etc. The first compound used may
be, for example, a compound having, in its molecule, a structure
represented by the formula (1) or (2) below.
##STR00001##
[0091] In the formula (1), R.sub.1 is a group containing an atom
such as C, N, S, O, Si, P, or Ti. The group containing such an atom
is, for example, a hydrocarbon group, a sulfo group (including a
sulfonate), a sulfonyl group, a sulfonamide group, a carboxylic
acid group (including a carboxylate), an amino group, an amide
group, a phosphoric acid group (including a phosphate and a
phosphoric ester), a phosphino group, a silanol group, an epoxy
group, an isocyanate group, a cyano group, a thiol group, or a
hydroxyl group. R.sub.2 is a group having at least 2 carbon atoms
and is, for example, a group containing an atom such as C, N, S, O,
Si, P, or Ti. The group containing such an atom is, for example, a
hydrocarbon group, a sulfo group (including a sulfonate), a
sulfonyl group, a sulfonamide group, a carboxylic acid group
(including a carboxylate), an amino group, an amide group, a
phosphoric acid group (including a phosphate and a phosphoric
ester), a phosphino group, a silanol group, an epoxy group, an
isocyanate group, a cyano group, a thiol group, or a hydroxyl
group.
##STR00002##
[0092] In the formula (2), R.sub.1 and R.sub.2 are each
independently a group containing an atom such as C, N, S, O, Si, P,
or Ti. The group containing such an atom is, for example, a
hydrocarbon group, a sulfa group (including a sulfonate), a
sulfonyl group, a sulfonamide group, a carboxylic acid group
(including a carboxylate), an amino group, an amide group, a
phosphoric acid group (including a phosphate and a phosphoric
ester), a phosphino group, a silanol group, an epoxy group, an
isocyanate group, a cyano group, a thiol group, or a hydroxyl
group.
(Second Compound)
[0093] The second compound has a cyclic hydrocarbon group. The
cyclic hydrocarbon group may be, for example, an unsaturated cyclic
hydrocarbon group or a saturated cyclic hydrocarbon group and may
have, in its molecule, both an unsaturated cyclic hydrocarbon group
and a saturated cyclic hydrocarbon group. The anti-smudge layer 12
may contain both a second compound having an unsaturated cyclic
hydrocarbon group and a second compound having a saturated cyclic
hydrocarbon group. The cyclic hydrocarbon group may be any of a
monocyclic hydrocarbon group and a polycyclic hydrocarbon group.
The cyclic hydrocarbon group may have an additional substituent.
Examples of the additional substituent may include a hydrocarbon
group, a sulfo group (including sulfonates), a sulfonyl group, a
sulfonamide group, a carboxylic acid group (including
carboxylates), an amino group, an amide group, a phosphoric acid
group (including phosphates and phosphoric esters), a phosphino
group, a silanol group, an epoxy group, an isocyanate group, a
cyano group, a thiol group, and a hydroxyl group. The second
compound may be an organic material, an organic-inorganic composite
material, a macromolecular material, or a monomolecular material,
so long as the second compound has a cyclic hydrocarbon group. No
particular limitation is imposed on the molecular structure of the
second compound so long as it has a cyclic hydrocarbon group, and
the second compound may have any functional group, any bonding
site, any hetero atom, any halogen atom, any metal atom, etc.
Examples of the saturated cyclic hydrocarbon group may include
groups having 5 or more carbon atoms and having monocyclo, bicyclo,
tricyclo, and tetracyclo structures and similar structures. More
specific examples thereof may include a cyclopentyl group, a
cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a
cyclononyl group, a cyclodecyl group, a cyclododecyl group, an
adamantyl group, a noradamantyl group, a tricyclodecyl group, a
tetracyclododecyl group, a norbornyl group, an isobornyl group, and
a steroid group. Examples of the unsaturated cyclic hydrocarbon
group may include a phenyl group, a naphthyl group, a pyrenyl
group, a pentacenyl group, and an anthryl group.
[0094] For example, a compound having, in its molecule, a structure
represented by the formula (3) below may be used as the organic
material.
##STR00003##
[0095] For example, a compound having, in its molecule, a structure
represented by the formula (4) below may be used as the
organic-inorganic composite material.
##STR00004##
(Third Compound)
[0096] The third compound has a chain hydrocarbon group (an acyclic
hydrocarbon group) at its terminal end. The chain hydrocarbon group
is, for example, any of an unsaturated chain hydrocarbon group and
a saturated chain hydrocarbon group, and the third compound may
contain, in its molecule, both an unsaturated chain hydrocarbon
group and a saturated chain hydrocarbon group. The chain
hydrocarbon group may be a linear chain hydrocarbon group or a
branched chain hydrocarbon group, and the third compound may
contain, in its molecule, both a linear chain hydrocarbon group and
a branched chain hydrocarbon group. The chain hydrocarbon group may
have an additional substituent. Examples of the additional
substituent may include a hydrocarbon group, a sulfo group
(including sultanates), a sulfonyl group, a sulfonamide group, a
carboxylic acid group (including a carboxylate), an amino group, an
amide group, a phosphoric acid group (including phosphates and
phosphoric esters), a phosphino group, a silanol group, an epoxy
group, an isocyanate group, a cyano group, a thiol group, and a
hydroxyl group.
[0097] Any of an organic material, an organic-inorganic composite
material, a macromolecular material, and a monomolecular material
may be used as the third compound, so long as it is a compound
having a chain hydrocarbon group at its terminal end. No particular
limitation is imposed on the molecular structure of the third
compound so long as it has a chain hydrocarbon group at its
terminal end, and the third compound may have any functional group,
any bonding site, any hetero atom, any halogen atom, any metal
atom, etc. Examples of the unsaturated chain hydrocarbon group may
include unsaturated chain hydrocarbon groups having at least 2
carbon atoms. Specific examples thereof may include a propene
group, a butene group, a pentene group, a hexene group, a heptene
group, an octene group, a decene group, a dodecene group, a
tetradecane group, a hexadecene group, an octadecene group, and a
docosene group. Examples of the saturated chain hydrocarbon group
may include saturated chain hydrocarbon groups having at least 2
carbon atoms. More specific examples thereof may include an ethyl
group, a propyl group, an isopropyl group, a butyl group, an
isobutyl group, a pentyl group, an isopentyl group, a hexyl group,
an isohexyl group, a heptyl group, an isoheptyl group, an octyl
group, an isooctyl group, a nonyl group, an isononyl group, a decyl
group, an isodecyl group, a dodecyl group, an isododecyl group, a
lauryl group, a tridecyl group, an isotridecyl group, a myristyl
group, an isomyristyl group, a cetyl group, an isocetyl group, a
stearyl group, an isostearyl group, an arachidyl group, an
isoarachidyl group, a behenyl group, an isobehenyl group, and a
cholesterol group.
[0098] For example, a compound having, in its molecule, a structure
represented by the formula (5) below may be used as the organic
material.
##STR00005##
[0099] For example, a compound having, in its molecule, a structure
represented by the formula (6) below may be used as the
organic-inorganic composite material.
##STR00006##
(Method of Examining Fingerprint Resistant Surface)
[0100] Whether or not the anti-smudge substrate has a fingerprint
resistant surface S can be examined, for example, as follows.
First, dynamic contact angles on the surface of the anti-smudge
substrate are measured to examine whether or not the advancing
contact angle of oleic acid is in the range of 15.degree. or less
and the receding contact angle of oleic acid is in the range of
10.degree. or less. Then, when the advancing contact angle of oleic
acid and the receding contact angle of oleic acid are within the
above ranges, it can be judged that the anti-smudge substrate has a
fingerprint resistant surface S. The surface shape of the
fingerprint resistant surface S can be examined by surface
observation under a scanning electron microscope or an atomic force
microscope.
[0101] The following examination is also possible.
[0102] First, the material of the surface of the anti-smudge
substrate is extracted with a solvent and subjected to composition
analysis by Gas Chromatograph-Mass Spectrometry (GC-MASS). When at
least one of the first and second compounds described above is
detected, it can be judged that the anti-smudge substrate has a
fingerprint resistant surface S.
[0103] A combination of the two examination methods described above
may be used to examine whether or not the anti-smudge substrate has
a fingerprint resistant surface S.
[Configuration of Master]
[0104] FIG. 2A is a perspective view illustrating an example of a
configuration of a master roll. FIG. 2B is an enlarged plan view
illustrating part of the master roll shown in FIG. 2A. FIG. 2C is a
cross-sectional view in a track T in FIG. 2B. The master roll 31 is
a master for producing an anti-smudge substrate having the
configuration described above and more specifically is a master for
molding a plurality of protrusions 12a on the surface of the
substrate described above. The master roll 31 has, for example, a
circular columnar or tubular shape, and the circular columnar or
tubular surface is a molding surface for molding a plurality of
protrusions 12a on the surface of the substrate. A plurality of
structures 32, for example, are arranged two-dimensionally on the
molding surface. The structures 32 are recessed from the molding
surface. The material used for the master roll 31 can be, for
example, glass, but the material is not particularly limited
thereto.
[0105] The plurality of structures 32 arranged on the molding
surface of the master roll 31 and the plurality of protrusions 12a
arranged on the surface of the substrate 11 described above have an
inverted concave-convex relationship with each other. In other
words, the arrangement, size, shape, arrangement pitch, height,
aspect ratio, etc. of the structures 32 of the master roll 31 are
the same as those of the protrusions 12a of the substrate 11.
[Configuration of Exposure Apparatus]
[0106] FIG. 3 is a schematic diagram illustrating an exemplary
configuration of a master roll exposure apparatus for producing the
master roll. This master roll exposure apparatus is configured on
the basis of an optical disc recording apparatus.
[0107] A laser light source 41 is a light source for light exposure
of a layer of a resist formed on the surface of the master roll 31
used as a recording medium and emits, for example, recording laser
light 34 having a wavelength .lamda.=266 nm. The laser light 34
emitted from the laser light source 41 travels in a straight line
as a collimated beam and is incident on an electro optical
modulator (EOM) 42. The laser light 34 passing through the electro
optical modulator 42 is reflected from a mirror 43 and guided to a
modulation optical system 45.
[0108] The mirror 43 includes a polarization beam splitter and has
the function of reflecting one of polarized components and allowing
the other polarized component to pass therethrough. The polarized
component passing through the mirror 43 is received by a photodiode
44, and the electro optical modulator 42 is controlled on the basis
of the received light signal to perform phase modulation of the
laser light 34.
[0109] In the modulation optical system 45, the laser light 34 is
focused on an acousto-optic modulator (AOM) 47 formed of glass
(SiO.sub.2) etc. through a condenser lens 46. The laser light 34 is
subjected to intensity modulation through the acousto-optic
modulator 47, diverged, and then converted to a collimated beam
through a lens 48. The laser light 34 emitted from the modulation
optical system 45 is reflected from a mirror 51 and guided to a
movable optical table 52 horizontally and parallel.
[0110] The movable optical table 52 includes a beam expander 53 and
an objective lens 54. The laser light 34 guided to the movable
optical table 52 is shaped into a desired beam shape by the beam
expander 53 and then directed onto a resist layer on the master
roll 31 through the objective lens 54. The master roll 31 is placed
on a turntable 56 connected to a spindle motor 55. The step of
exposing the resist layer to light is performed by rotating the
master roll 31 and irradiating the resist layer intermittently with
the laser light 34 while the laser light 34 is moved in a direction
of the height of the master roll 31. Latent images formed have a
substantially elliptic shape with a major axis extending in a
circumferential direction. The laser light 34 is moved by moving
the movable optical table 52 in the direction of an arrow R.
[0111] The exposure apparatus includes a control mechanism 57 for
forming, on the resist layer, latent images corresponding to the
two-dimensional pattern of the plurality of protrusions 12a
described above. The control mechanism 57 includes a formatter 49
and a driver 50. The formatter 49 includes a polarity inversion
unit, and the polarity inversion unit controls the timing of
irradiation of the resist layer with the laser light 34. The driver
50 controls the acousto-optic modulator 47 in response to the
output from the polarity inversion unit.
[0112] In this master roll exposure apparatus, a polarity inversion
formatter signal is synchronized with a rotation controller to
generate a signal for each track such that the two-dimensional
pattern is spatially linked, and intensity modulation is performed
by the acousto-optic modulator 47. By performing patterning at a
constant angular velocity (CAV), an appropriate number of
revolutions, an appropriate modulation frequency, and an
appropriate feed pitch, a two-dimensional pattern such as a
hexagonal lattice pattern can be recorded.
[Method of Producing Anti-Smudge Substrate]
[0113] FIGS. 4A to 7C are process diagrams illustrating an example
of the method of producing the anti-smudge substrate according to
the first embodiment in the present technique.
(Resist Layer Forming Step)
[0114] First, as shown in FIG. 4A, a circular columnar or tubular
master roll 31 is prepared. The master roll 31 is, for example, a
glass master. Next, as shown in FIG. 4B, a resist layer 33 is
formed on the surface of the master roll 31. The material used for
the resist layer 33 may be, for example, any of organic resists and
inorganic resists. For example, a novolac-based resist or a
chemically-amplified resist may be used as the organic resist. For
example, a metal compound may be used as the inorganic resist.
(Exposure Step)
[0115] Next, as shown in FIG. 4C, the resist layer 33 formed on the
surface of the master roll 31 is irradiated with the laser light
(exposure beam) 34. Specifically, the master roll 31 is placed on
the turntable 56 of the master roll exposure apparatus shown in
FIG. 3. Then, while the master roll 31 is rotated, the resist layer
33 is irradiated with the laser light (exposure beam) 34. In this
case, the resist layer 33 is intermittently irradiated with the
laser light 34 while the laser light 34 is moved in the height
direction of the master roll 31 (a direction parallel to the center
axis of the circular columnar or tubular master roll 31), whereby
the entire surface of the resist layer 33 is exposed to the light.
In this manner, latent images 35 corresponding to the trajectory of
the laser light 34 are formed over the entire surface of the resist
layer 33.
[0116] For example, the latent images 35 are arranged on the
surface of the master roll so as to form a plurality of tracks and
are formed into a regular periodic pattern with prescribed unit
cells Uc. The latent images 35 have, for example, a circular or
elliptic shape. When the latent images 35 have an elliptic shape,
it is preferable that the elliptic shape have a major axis
direction in the extending direction of the tracks T.
(Development Step)
[0117] Next, for example, a developer is dropped onto the resist
layer 33 while the master roll 31 is rotated to thereby subject the
resist layer 33 to development treatment. In this manner, a
plurality of openings are formed in the resist layer 33, as shown
in FIG. 5A. When a positive resist is used to form the resist layer
33, exposed portions exposed to the laser light 34 have a higher
rate of dissolution in the developer than non-exposed portions, and
therefore a pattern corresponding to the latent images (exposed
portions) is formed in the resist layer 33, as shown in FIG. 5A.
The pattern of the openings is, for example, a regular periodic
pattern with prescribed unit cells Uc.
(Etching Step)
[0118] Next, the surface of the master roll 31 is etched using, as
a mask, the pattern of the resist layer 33 (resist pattern) formed
on the master roll 31. In this manner, structures (recessed
portions) 32 having a cone shape can be obtained, as shown in FIG.
5B. Preferably, the cone shape is, for example, an elliptic cone or
truncated elliptic cone shape with its major axis direction in the
extending direction of the tracks T. For example, the etching used
may be dry etching or wet etching. In this case, by performing
etching treatment and ashing treatment alternately, a pattern of
cone-shaped structures 32, for example, can be formed. The intended
master roll 31 can thereby be obtained.
(Structure Forming Step)
[0119] Next, the master roll 31 obtained as described above is used
to perform shape transfer onto a resin material. A plurality of
protrusions 12a are thereby formed on the surface of the substrate
11, whereby the above-described anti-smudge substrate according to
the first embodiment is produced. The shape transfer method used
may be, for example, a transfer method using an energy ray-curable
resin (hereinafter referred to as an "energy ray transfer method"),
a transfer method using a thermosetting resin (hereinafter referred
to as a "thermosetting transfer method"), or a transfer method
using a thermoplastic resin composition (hereinafter referred to as
a "thermal transfer method"). The energy ray transfer method is
meant to include a 2P transfer method (Photo Polymerization: a
shape imparting method using photo-curing). Hereinafter, the
structure forming step will be described for two different cases,
i.e., a structure forming step using the energy ray transfer method
or the thermosetting transfer method and a structure forming step
using the thermal transfer method.
[Structure Forming Step Using Energy Ray Transfer Method or
Thermosetting Transfer Method]
(Step of Preparing Resin Composition)
[0120] FIGS. 6A to 6C are process diagrams illustrating an example
of the structure forming step using the energy ray transfer method
or the thermosetting transfer method. First, if necessary, a resin
composition is dissolved in a solvent to dilute the resin
composition. In this case, various additives may be added to the
resin composition as needed. The dilution with the solvent is
performed optionally. When no dilution is necessary, the resin
composition may be used without any solvent.
[0121] The resin composition contains at least one of an energy
ray-curable resin composition and a thermosetting resin
composition. The energy ray-curable resin composition means a resin
composition that can be cured by irradiation with energy rays. The
energy rays are those that can trigger a polymerization reaction of
radicals, cations, anions etc. and are energy rays such as an
electron beam, ultraviolet rays, infrared rays, a laser beam,
visible light, ionizing radiation (X-rays, .alpha.-rays,
.beta.-rays, .gamma.-rays etc.), microwaves, or high-frequency
waves. If necessary, the energy ray-curable resin composition used
may be mixed with another resin composition and, for example, may
be mixed with another curable resin composition such as a
thermosetting resin composition. The energy ray-curable resin
composition may be an organic-inorganic hybrid material. A mixture
of two or more types of energy ray-curable resin compositions may
be used. Preferably, the energy ray-curable resin composition used
is an ultraviolet ray-curable resin composition that is cured by
irradiation with ultraviolet rays.
[0122] The energy ray-curable resin composition and the
thermosetting resin contain, for example, at least one of the first
compound having an ester linkage in a portion other than terminal
ends and the second compound having a cyclic hydrocarbon group.
Preferably, from the viewpoint of improving the ease of wiping off
fingerprints, the energy ray-curable resin composition and/or the
thermosetting resin further contain the third compound having a
chain hydrocarbon group at its terminal end in addition to the
second compound.
[0123] When the resin composition further contains an additive
(including an initiator) in addition to a base resin, the first,
second, and third compounds may be additives. In this case, the
additive is preferably a leveling agent.
[0124] The ultraviolet ray-curable resin composition contains, for
example, an initiator and a (meth)acrylate having a (meth)acryloyl
group. The (meth)acryloyl group means an acryloyl group or a
methacryloyl group. The (meth)acrylate means an acrylate or a
methacrylate. The ultraviolet ray-curable resin composition
contains, for example, a monofunctional monomer, a bifunctional
monomer, a polyfunctional monomer, etc. More specifically, the
ultraviolet ray-curable resin composition is one of the materials
shown below or a mixture of two or more thereof.
[0125] Examples of the monofunctional monomer may include
carboxylic acids (acrylic acid), hydroxy compounds (2-hydroxyethyl
acrylate, 2-hydroxypropyl acrylate, and 4-hydroxybutyl acrylate),
alkyls, alicyclic compounds (isobutyl acrylate, t-butyl acrylate,
isooctyl acrylate, lauryl acrylate, stearyl acrylate, isobornyl
acrylate, and cyclohexyl acrylate), other functional monomers
(2-methoxyethyl acrylate, methoxy ethylene glycol acrylate,
2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, benzyl
acrylate, ethylcarbitol acrylate, phenoxyethyl acrylate,
N,N-dimethylaminoethyl acrylate, N,N-dimethylaminopropyl
acrylamide, N,N-dimethyl acrylamide, acryloylmorpholine,
N-isopropylacrylamide, N,N-diethylacrylamide, N-vinylpyrrolidone,
2-(perfluorooctyl)ethyl acrylate, 3-perfluorohexyl-2-hydroxypropyl
acrylate, 3-perfluorooctyl-2-hydroxypropyl acrylate,
2-(perfluorodecyl)ethyl acrylate, 2-(perfluoro-3-methylbutyl)ethyl
acrylate), 2,4,6-tribromophenol acrylate, 2,4,6-tribromophenol
methacrylate, 2-(2,4,6-tribromophenoxy)ethyl acrylate, and
2-ethylhexyl acrylate).
[0126] Examples of the bifunctional monomer may include
tri(propylene glycol)diacrylate, trimethylolpropane diallyl ether,
and urethane acrylate.
[0127] Examples of the polyfunctional monomer may include
trimethylolpropane triacrylate, dipentaerythritol pentaacrylate,
dipentaerythritol hexaacrylate, and ditrimethylolpropane
tetraacrylate.
[0128] Examples of the initiator may include
2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl phenyl
ketone, and 2-hydroxy-2-methyl-l-phenylpropane-1-one.
[0129] From the viewpoint of, for example, the applicability and
stability of the resin component and the smoothness of the coating,
the solvent used is mixed into the resin composition. As the
solvent, water or organic solvent can be used. More specifically,
the solvent used is, for example, one or a mixture of two or more
of: aromatic-based solvents such as toluene and xylene;
alcohol-based solvents such as methyl alcohol, ethyl alcohol,
n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, iso-butyl
alcohol, and propylene glycol monomethyl ether; ester-based
solvents such as methyl acetate, ethyl acetate, butyl acetate, and
cellosolve acetate; ketone-based solvents such as acetone, methyl
ethyl ketone, methyl isobutyl ketone, and cyclohexanone; glycol
ethers such as 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol,
ethylene glycol dimethyl ether, ethylene glycol diethyl ether,
diethylene glycol dimethyl ether, and propylene glycol methyl
ether; glycol ether esters such as 2-methoxyethyl acetate,
2-ethoxyethyl acetate, 2-butoxyethyl acetate, and propylene glycol
methyl ether acetate; chlorine-based solvents such as chloroform,
dichloromethane, trichloromethane, and methylene chloride;
ether-based solvents such as tetrahydrofuran, diethyl ether,
1,4-dioxane, and 1,3-dioxolane; N-methylpyrrolidone;
dimethylformamide; dimethyl sulfoxide; and dimethylacetamide. To
suppress drying spots and cracks on the coated surface, a
high-boiling point solvent may be further added to control the
evaporation rate of the solvents. Examples of such a solvent may
include butyl cellosolve, diacetone alcohol, butyl triglycol,
propylene glycol monomethyl ether, propylene glycol monoethyl
ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl
ether, ethylene glycol monoisopropyl ether, diethylene glycol
monobutyl ether, diethylene glycol monoethyl ether, diethylene
glycol monomethyl ether, diethylene glycol diethyl ether,
dipropylene glycol monomethyl ether, tripropylene glycol monomethyl
ether, propylene glycol monobutyl ether, propylene glycol isopropyl
ether, dipropylene glycol isopropyl ether, tripropylene glycol
isopropyl ether, and methyl glycol. These solvents may be used
singly or in combination of two or more.
(Application Step)
[0130] Next, the prepared resin composition 36 is applied to or
printed on the surface of a substrate as shown in FIG. 6A. The
application method used may be, for example, wire bar coating,
blade coating, spin coating, reverse roll coating, die coating,
spray coating, roll coating, gravure coating, micro-gravure
coating, lip coating, air knife coating, curtain coating, a comma
coating method, or a dipping method. The printing method used may
be, for example, a letterpress printing method, an offset printing
method, a gravure printing method, an intaglio printing method, a
rubber plate printing method, an inkjet method, or a screen
printing method.
(Drying Step)
[0131] Next, if the resin composition 36 contains a solvent, the
resin composition is dried to volatilize the solvent, as necessary.
No particular limitation is imposed on the drying conditions, and
any of natural drying and artificial drying in which drying
temperature and drying time are controlled may be used. However, it
is preferable that when wind is blown onto the surface of the
coating during drying, the wind be blown such that no wind ripples
occur on the coating surface. The drying temperature and the drying
time can be appropriately determined from the boiling point of the
solvent contained in the coating. In this case, it is preferable to
select the drying temperature and the drying time within the range
in which no deformation of the substrate 11 due to thermal
contraction occurs, in consideration of the heat resistance of the
substrate 11.
(Curing Step)
[0132] Next, as shown in FIG. 6B, the master roll 31 and the resin
composition 36 applied to the surface of the substrate 11 are
brought into close contact with each other, and the resin
composition 36 is cured. Then the substrate 11 integrated with the
cured resin composition 36 is peeled off. In this manner, an
anti-smudge substrate in which a plurality of protrusions 12a are
formed on the surface of the substrate 11 is obtained, as shown in
FIG. 6C. In this case, a base layer 12b may be further formed
between the protrusions 12a and the substrate 11, if necessary.
[0133] Different curing methods are used for different types of
resin compositions 36. When the resin composition 36 used is an
energy ray-curable resin composition, the master roll 31 is pressed
against the resin composition 35 to bring them into close contact
with each other, and then the resin composition 36 is irradiated
with energy rays such as ultraviolet rays (ultraviolet light) from
an energy ray source 37 to thereby cure the resin composition
36.
[0134] No particular limitation is imposed on the energy ray source
37, so long as it can emit energy rays such as an electron beam,
ultraviolet rays, infrared rays, a laser beam, visible light, gamma
rays, ionizing radiation (X-rays, .alpha.-rays, .beta.-rays,
.gamma.-rays, etc.), microwaves, or high-frequency waves, and
ultraviolet rays are preferred from the viewpoint of a production
facility. Preferably, the cumulative amount of irradiation is
appropriately selected in consideration of the curing properties of
the resin composition and suppression of yellowing of the resin
composition and the substrate 11. Preferably, the atmosphere during
irradiation is appropriately selected according to the type of the
resin composition. Examples of the atmosphere may include air and
inert gas atmospheres such as nitrogen and argon atmospheres.
[0135] When the substrate 11 is formed of a material that does not
transmit energy rays such as ultraviolet rays, the master roll 31
may be formed of a material (for example, quartz) that can transmit
the energy rays, and the resin composition 36 may be irradiated
with the energy rays from the inner side of the master roll 31. The
master for transfer is not limited to the master roll 31 described
above, and a flat master may be used. However, from the viewpoint
of improvement in mass productivity, it is preferable to use the
above-described master roll 31 as the master for transfer.
[0136] When the resin composition 36 used is a thermosetting resin
composition, the master roll 31 is pressed against the resin
composition 36 to bring them into close contact with each other,
and then the resin composition 36 is heated to its curing
temperature using the master roll 31 to thereby cure the resin
composition 36. In this case, a cooling roll may be pressed against
the surface of the substrate 11 that is opposite to the side onto
which the resin composition 36 is applied or printed to thereby
prevent thermal defects in the substrate 11. The master roll 31
includes a heat source such as a heater disposed thereinside and is
therefore configured so as to be capable of heating the resin
composition 36 in close contact with the molding surface of the
master roll 31.
[Structure Forming Step Using Thermal Transfer Method]
[0137] FIGS. 7A to 7C are process diagrams illustrating an example
of the structure forming step using the thermal transfer method.
First, as shown in FIG. 7A, a substrate 11 in which a resin layer
37 serving as a transfer layer is formed on its surface is formed.
The resin layer 37 contains, for example, a thermoplastic resin
composition. The thermoplastic resin composition contains at least
one of the first compound and the second compound. When the
thermoplastic resin composition contains the second compound, it is
preferable that the thermoplastic resin composition further contain
the third compound together with the second compound.
[0138] Next, as shown in FIG. 7B, the master roll 31 is pressed
against the resin layer 37 to bring them into close contact with
each other. Then, for example, the resin layer 37 is heated to near
its glass transition point or to a temperature equal to or higher
than the glass transition point to transfer the shape of the
molding surface of the master roll 31. Next, the resin layer 37
with the shape transferred thereto together with the substrate 11
is peeled off the master roll 31. An anti-smudge substrate in which
a plurality of protrusions 12a are formed on the surface of the
substrate 11 is thereby obtained, as shown in FIG. 7C. In this
case, a base layer 12b may be further formed between the
protrusions 12a and the substrate 11, if necessary. In addition, a
cooling roll may be pressed against the surface of the substrate 11
that is opposite to the side on which the resin layer 37 is
disposed to thereby prevent thermal defects in the substrate
11.
[Effects]
[0139] In the first embodiment, the anti-smudge layer 12 contains
at least one of the first compound having an ester linkage in a
portion other than its terminal ends and the second compound having
a cyclic hydrocarbon group, and a plurality of protrusions 12a are
disposed on the fingerprint resistant surface S of the anti-smudge
layer 12. Therefore, when fingerprints adhere to the fingerprint
resistant surface S of the anti-smudge substrate, the fingerprint
patterns spread spontaneously and become less noticeable.
[0140] When the average height Hm of the protrusions 12a is 100 nm
or smaller, fingerprints adhering to the fingerprint resistant
surface S of the anti-smudge substrate can be made less noticeable
by rubbing the fingerprints with, for example, a finger to spread
them thinly. Therefore, the ease of wiping off fingerprints with a
finger etc. can be improved. When the anti-smudge substrate or its
anti-smudge layer 12 is applied to an electronic device such as an
input device or a display device, fingerprints can become less
noticeable over time during use of the device. Therefore, an
electronic device having high fingerprint resistance can be
provided.
[Modifications]
[0141] In the first embodiment described above, the example of the
configuration in which the anti-smudge layer 12 contains both the
second compound having a cyclic hydrocarbon group and the third
compound having a chain hydrocarbon group at a terminal end has
been described. However, the present technique is not limited to
this example. A configuration in which the anti-smudge layer 12
contains a fourth compound having a cyclic hydrocarbon group and a
chain hydrocarbon group at a terminal end may be employed. Also in
this case, the ease of wiping off fingerprints similar to that in
the first embodiment described above can be obtained.
[0142] In the example of the configuration described in the above
first embodiment, the anti-smudge layer 12 is provided adjacent to
the surface of the substrate 11, but the configuration of the
anti-smudge substrate is not limited to this example. Modifications
of the anti-smudge substrate will next be described.
(First Modification)
[0143] FIG. BA is a cross-sectional view illustrating an example of
a configuration of an anti-smudge substrate according to a first
modification. As shown in FIG. BA, this anti-smudge substrate is
different from the anti-smudge substrate according to the first
embodiment in that an anchor layer disposed between the substrate
11 and the anti-smudge layer 12 is further provided. When the
anchor layer disposed between the substrate 11 and the anti-smudge
layer 12 is provided as described above, the adhesion between the
substrate 11 and the anti-smudge layer 12 can be improved. A
plurality of protrusions 12a may be formed by providing
protrusion-like fine structures on the surface of the anchor layer
and forming an anti-smudge layer 12 so as to conform to the fine
structures.
[0144] The material of the anchor layer used can be selected from,
for example, a wide variety of known natural macromolecular resins
and synthetic macromolecular resins. For example, transparent
thermoplastic resin compositions, ionizing radiation irradiation
compositions, and transparent curable resin compositions that are
cured by heat can be used as the above resins. Examples of the
usable thermoplastic resin composition may include polyvinyl
chloride, vinyl chloride-vinyl acetate copolymers, polymethyl
methacrylate, nitrocellulose, chlorinated polyethylene, chlorinated
polypropylene, ethyl cellulose, and hydroxypropyl methyl cellulose.
Examples of the usable transparent curable resin may include
methacrylates, melamine acrylate, urethane acrylate, isocyanates,
epoxy resin, and polyimide resin. The ionizing radiation used may
be an electron beam, light (for example, ultraviolet rays or
visible light), gamma rays, and X-rays, and ultraviolet rays are
preferred from the viewpoint of a production facility.
[0145] The material of the anchor layer may further contain an
additive. Examples of the additive may include a surfactant, a
viscosity modifier, a dispersant, a curing-accelerating catalyst, a
plasticizer, and stabilizers such as an antioxidant and an
anti-sulfuration agent.
(Second Modification)
[0146] FIG. 8B is a cross-sectional view illustrating an example of
a configuration of an anti-smudge substrate according to a second
modification. As shown in. FIG. 8B, this anti-smudge substrate is
different from the anti-smudge substrate according to the first
embodiment in that a hard coating layer 14 disposed between the
substrate 11 and the anti-smudge layer 12 is further provided. It
is particularly preferable to provide the hard coating layer 14
when the substrate 11 used is a resin substrate such as a plastic
film. When the hard coating layer 14 is disposed between the
substrate 11 and the anti-smudge layer 12 as described above,
practical properties (such as durability and pencil hardness) can
be improved. A plurality of protrusions 12a may be formed by
providing protrusion-like fine structures on the surface of the
hard coating layer 14 and forming an anti-smudge layer 12 so as to
conform to the fine structures.
[0147] The material of the usable hard coating layer 14 can be
selected from, for example, a wide variety of known natural
macromolecular resins and synthetic macromolecular resins. For
example, transparent thermoplastic resin compositions and
transparent curable resins that are cured by heat or irradiation
with ionizing radiation can be used as the above resins. Examples
of the usable thermoplastic resin composition may include polyvinyl
chloride, vinyl chloride-vinyl acetate copolymers, polymethyl
methacrylate, nitrocellulose, chlorinated polyethylene, chlorinated
polypropylene, ethyl cellulose, and hydroxypropyl methyl cellulose.
Examples of the usable transparent curable resin may include
methacrylates, melamine acrylate, urethane acrylate, isocyanates,
epoxy resin, and polyimide resin. The ionizing radiation used may
be an electron beam, light (for example, ultraviolet rays or
visible light), gamma rays, or X-rays, and ultraviolet rays are
preferred from the viewpoint of a production facility.
[0148] The material of the hard coating layer 14 may further
contain an additive. Examples of the additive may include a
surfactant, a viscosity modifier, a dispersant, a
curing-accelerating catalyst, a plasticizer, and stabilizers such
as an antioxidant and an anti-sulfuration agent. The hard coating
layer 14 may further contain light-scattering particles such as an
organic resin filler that scatter light, in order to impart an AG
(Anti-Glare) function to the fingerprint resistant surface S. In
this case, the light-scattering particles may protrude from the
surface of the hard coating layer 14 or the fingerprint resistant
surface S of the anti-smudge layer 12 or may be covered with a
resin contained in the hard coating layer 14 or the anti-smudge
layer 12. The light-scattering particles may or may not be in
contact with the substrate 11, which is a lower layer. Both the
hard coating layer 14 and the anti-smudge layer 12 may further
contain light-scattering particles. Instead of or in addition to
the AG (Anti-Glare) function, an AR (Anti-Reflection) function may
be imparted to the anti-smudge substrate. The AR (Anti-Reflection)
function can be imparted by, for example, forming an AR layer on
the hard coating layer 14. The AR layer used may be, for example, a
single low-refractive index layer film or a multilayer film formed
by alternately stacking low-refractive index layers and
high-refractive index layers.
(Third Modification)
[0149] FIG. 80 is a cross-sectional view illustrating an example of
a configuration of an anti-smudge substrate according to a third
modification. As shown in FIG. 8C, this anti-smudge substrate is
different from the anti-smudge substrate according to the first
embodiment in that a hard coating layer 14 disposed between the
substrate 11 and the anti-smudge layer 12 and an anchor layer
disposed between the substrate 11 and the hard coating layer 14 are
further provided. It is particularly preferable to provide the hard
coating layer 14 when the substrate 11 used is a resin substrate
such as a plastic film.
(Fourth Modification)
[0150] FIG. 9A is a cross-sectional view illustrating an example of
a configuration of an anti-smudge substrate according to a fourth
modification. As shown in FIG. 9A, this anti-smudge substrate is
different from the anti-smudge substrate according to the first
embodiment in that hard coating layers 14 are further provided on
both the surfaces of the substrate 11. The anti-smudge layer 12 is
disposed on the surface of one of the hard coating layers 14
disposed on both the surfaces of the substrate 11. It is
particularly preferable to provide the hard coating layers 14 when
the substrate 11 used is a resin substrate such as a plastic
film.
(Fifth Modification)
[0151] FIG. 9B is a cross-sectional view illustrating an example of
a configuration of an anti-smudge substrate according to a fifth
modification. As shown in FIG. 9B, this anti-smudge substrate is
different from the anti-smudge substrate according to the first
embodiment in that anchor layers and hard coating layers 14 are
further provided on both the surfaces of the substrate 11. Each
anchor layer is disposed between the substrate 11 and a hard
coating layer 14. The anti-smudge layer 12 is disposed on the
surface of one of the hard coating layers 14 disposed on both the
surfaces of the substrate 11. It is particularly preferable to
provide the hard coating layers 14 when the substrate 11 used is a
resin substrate such as a plastic film.
(Sixth Modification)
[0152] FIG. 9C is a cross-sectional view illustrating an example of
a configuration of an anti-smudge substrate according to a sixth
modification. This anti-smudge substrate is an anti-smudge
transparent conductive substrate and is different from the
anti-smudge substrate according to the first embodiment in that a
transparent conductive layer 15 is further provided on the surface
of the substrate 11 that is opposite to the anti-smudge layer 12,
as shown in FIG. 9C. The transparent conductive layer 15 may be a
transparent electrode having a prescribed electrode pattern.
Examples of the electrode pattern may include, but are not limited
to, a stripe pattern. An over-coating layer may be further provided
on the surface of the transparent conductive layer 15, if
necessary. A hard coating layer and/or an anchor layer may be
further provided between the substrate 11 and the transparent
conductive layer 15, if necessary.
[0153] The material used for the transparent conductive layer 15
may be, for example, at least one selected from the group
consisting of electrically conductive metal oxide materials,
electrically conductive metal materials, electrically conductive
carbon materials, and conductive polymers. Examples of the metal
oxide materials may include indium tin oxide (ITO), zinc oxide,
indium oxide, antimony-doped tin oxide, fluorine-doped tin oxide,
aluminum-doped zinc oxide, gallium-doped zinc oxide, silicon-doped
zinc oxide, zinc oxide-tin oxide based materials, indium oxide-tin
oxide based materials, and zinc oxide-indium oxide-magnesium oxide
based materials. The metal material used may be, for example, a
metal nano-filler such as metal nanoparticles and metal nanowires.
Specific examples of the metal material may include: metals such as
copper, silver, gold, platinum, palladium, nickel, tin, cobalt,
rhodium, iridium, iron, ruthenium, osmium, manganese, molybdenum,
tungsten, niobium, tantalum, titanium, bismuth, antimony, and lead;
and alloys of these metals. Examples of the carbon materials may
include carbon black, carbon fibers, fullerenes, graphene, carbon
nanotubes, carbon microcoils, and carbon nanohorns. Examples of the
conductive polymers may include substituted or unsubstituted
polyaniline, substituted or unsubstituted polypyrrole, substituted
or unsubstituted polythiophene, and (co)polymers composed of one or
two selected from these polymers.
[0154] The method used to form the transparent conductive layer 15
may be, for example, a PVD method such as a sputtering method, a
vacuum deposition method, or an ion plating method, a CVD method, a
coating method, or a printing method, but the method used is not
limited thereto.
2. Second Embodiment
[0155] FIG. 10 is a cross-sectional view illustrating an example of
a configuration of an anti-smudge substrate according to the second
embodiment of the present technique. As shown in FIG. 10, this
anti-smudge substrate is different from that in the first
embodiment in that a substrate 21 is formed integrally with a
plurality of protrusions 22. The material used for the substrate 21
and the protrusions 22 is the same as the material for the
anti-smudge layer 12 in the first embodiment described above.
Specifically, it is preferable to use a material containing a
thermoplastic resin composition as the material of the substrate 21
and the protrusions 22. Preferably, in this case, the thermoplastic
resin composition contains at least one of the first compound and
the second compound. The substrate 21 and the protrusions 22 are
the same as the substrate 11 and the protrusions 12a in the first
embodiment described above except for the material constituting
them.
[0156] The method used to produce the anti-smudge substrate may be,
for example, a melt extrusion method, a transfer method, etc. The
melt extrusion method used may be, for example, a method in which,
immediately after the thermoplastic resin composition is discharged
from a die into a film shape, the thermoplastic resin composition
is nipped between two rolls to transfer the surface shape of the
roll to the resin material. One of the two rolls used may be the
master roll 31 in the first embodiment described above. The
transfer method used may be, for example, a thermal transfer method
in which the molding surface of a master is pressed against the
substrate and the substrate is heated to near its glass transition
point or to a temperature equal to or higher than the glass
transition point to thereby transfer the shape of the molding
surface of the master. The master used may be the master roll 31 in
the first embodiment described above.
[Effects]
[0157] In the second embodiment, the substrate 21 and the plurality
of protrusions 22 are formed integrally with each other, so that
the configuration of the anti-smudge substrate can be simplified.
When the substrate 21 and the plurality of protrusions 22 are
transparent, reflection from the interface between the substrate 21
and the plurality of protrusions 22 can be suppressed.
3. Third Embodiment
[Configuration of Anti-Smudge Substrate]
[0158] FIG. 11A is a cross-sectional view illustrating an example
of a configuration of an anti-smudge substrate according to a third
embodiment of the present technique. FIG. 11B is an enlarged
cross-sectional view of part of FIG. 11A. This anti-smudge
substrate includes a substrate 11 and an anti-smudge structure
layer 23 provided on the surface of the substrate 11. The
anti-smudge structure layer 23 includes a fine structure layer 24
provided on the surface of the substrate 11 and an anti-smudge
layer 25 provided on the fine structure surface of the fine
structure layer 24. In the third embodiment, the same portions as
those in the first embodiment are denoted by the same reference
numerals, and the description thereof is omitted.
[0159] A plurality of surface protrusions (first protrusions) 23a
are provided on the fingerprint resistant surface S of the
anti-smudge layer 25. A plurality of inner protrusions (second
protrusions) 24a are provided on the surface of the fine structure
layer 24. The surface protrusions 23a are configured by disposing
the anti-smudge layer 25 so as to conform to the inner protrusions
24a. The arrangement, shape, arrangement pitch (average arrangement
pitch), height (average height), aspect ratio (average aspect
ratio), etc. of the surface protrusions 23a are the same as those
of the protrusions 12a in the first embodiment described above. If
necessary, the fine structure layer 24 may further include a base
layer 24b between the surface of the substrate 11 and the inner
protrusions 24a. This anti-smudge substrate may have a
configuration in which the substrate 11 and the fine structure
layer 24 are integrally formed with each other.
[0160] The material of the anti-smudge layer 25 is the same as the
material of the anti-smudge layer 12 in the first embodiment. The
fine structure layer 24 may be a functional layer such as an anchor
layer or a hard coating layer. The material used for the fine
structure layer 24 may be at least one of an energy ray-curable
resin composition, a thermosetting resin composition, and a
thermoplastic resin composition. The thickness of the anti-smudge
layer 12 is selected such that, for example, when the anti-smudge
layer 25 is formed on the surface of the fine structure layer 24,
the shape of the inner protrusions 24a is not embedded in the fine
structure layer 24. Specifically, the thickness of the anti-smudge
layer 25 is, for example, equal to or larger than a monolayer
thickness and 10 .mu.m or smaller, preferably equal to or larger
than the monolayer thickness and 1 .mu.m or smaller, and
particularly preferably equal to or larger than the monolayer
thickness and 100 nm or smaller.
[Method of Producing Anti-Smudge Substrate]
[0161] Next, a method of producing the anti-smudge substrate having
the above-described configuration will be described.
[0162] First, the inner protrusions 24a are formed on the surface
of the substrate 11 in the same manner as in the first embodiment
described above except that a conventionally known energy
ray-curable resin or thermosetting resin not containing any of the
above described first compound and second compound is used.
However, the height, aspect ratio, etc. of the inner protrusions
24a are set such that the height, aspect ratio, etc. of the surface
protrusions 23a formed in the subsequent step become the same as
those of the protrusions 12a in the first embodiment described
above. In this step, a base layer 24b may be provided between the
surface of the substrate 11 and the inner protrusions 24a, if
necessary.
[0163] Next, a resin composition containing at least one of the
first compound having an ester linkage in a portion other than its
terminal ends and the second compound having a cyclic hydrocarbon
group is prepared. This resin composition used may be the same
resin composition as that used to form the anti-smudge layer 12 in
the first embodiment described above.
[0164] Next, the prepared resin composition is applied to or
printed onto the surface of the substrate 11 having the plurality
of inner protrusions 24a disposed thereon. In this case, the resin
composition is applied or printed so as to conform to the surface
shape of the inner protrusions 24a. When the next step includes a
drying step, the resin composition may conform to the surface shape
of the inner protrusions 24a after the drying step. Next, if
necessary, the resin composition is dried and then cured. The
anti-smudge layer 25 is thereby formed on the plurality of inner
protrusions 24a so as to conform to the surface of these inner
protrusions 24a. Specifically, a fingerprint resistant surface S
with the plurality of surface protrusions 23a is formed on the
surface of the substrate 11. The intended anti-smudge substrate is
obtained in the manner described above.
[Effects]
[0165] In the third embodiment, the anti-smudge layer 25 is
disposed so as to conform to the plurality of inner protrusions 24a
of the fine structure layer 24, and the plurality of surface
protrusions 23a are formed on the fingerprint resistant surface S.
Therefore, the same effects as those of the first embodiment
described above can be obtained.
4. Fourth Embodiment
[0166] FIGS. 12A to 12C are schematic diagrams illustrating
examples of configurations of an anti-smudge substrate according to
a fourth embodiment of the present technique. The anti-smudge
substrate according to the fourth embodiment is different from the
anti-smudge substrate according to the third embodiment in that an
adsorption compound 25a is adsorbed on the surface of the inner
protrusions 24a to thereby form an anti-smudge layer 25. A
functional layer (such as an anchor layer or a hard coating layer)
other than the anti-smudge layer 25 may be provided on the surface
of the substrate 11. The anti-smudge layer 25 is, for example, a
monomolecular layer formed from the adsorption compound 25a. The
region on which the adsorption compound 25a is adsorbed is not
limited to one of the surfaces of the substrate 11 where the inner
protrusions 24a are disposed, and the adsorption compound 25a may
be adsorbed on both the surfaces of the substrate 11 or part of the
surfaces. The adsorption compound 25a may be adsorbed selectively
on a surface or a predetermined region that are frequently touched
with a hand, a finger, etc.
[0167] The site of the adsorption compound 25a that is adsorbed on
the surface of the inner protrusions 24a may be any of the terminal
ends of the side and main chains of the adsorption compound 25a,
and both a terminal end of a side chain and a terminal end of the
main chain may be adsorbed on the surface of the substrate 11. FIG.
12A shows a configuration in which one terminal end of the main
chain of the adsorption compound 25a is adsorbed on the surface of
the inner protrusions 24a. FIG. 12B shows a configuration in which
terminal ends of side chains of the adsorption compound 25a are
adsorbed on the surface of the inner protrusions 24a. FIG. 12C
shows a configuration in which the main chain of the adsorption
compound 25a is adsorbed on the surface of the inner protrusions
24a. The adsorption may be any of physical adsorption and chemical
adsorption. From the viewpoint of durability, chemical adsorption
is preferred. Specific examples of the adsorption may include
adsorption through an acid-base reaction, a covalent bond, an ionic
bond, a hydrogen bond, etc.
[0168] The adsorption compound 25a used may be prepared by adding
an adsorption group that adsorbs on the surface of the substrate 11
to, for example, the first and second compounds in the first
embodiment described above. The position at which the adsorption
group is attached may be any of the terminal ends and side chains
of the adsorption compound 25a, and a plurality of adsorption
groups may be added to one molecule of the adsorption compound
25a.
[0169] Any adsorption group may be used so long as it can be
adsorbed to the inner protrusions 24a. Specific examples of the
adsorption group may include a sulfo group (including sulfonates),
a sulfonyl group, a carboxylic acid group (including carboxylates),
an amino group, a phosphoric acid group (including phosphates and
phosphoric esters), a phosphino group, an epoxy group, an
isocyanate group, and a thiol group. It is sufficient that at least
one such adsorption group be present in the adsorption compound
25a.
[0170] A compound having, in its molecule, a structure represented
by the formula (7) below can be used as the first compound having
an adsorption group.
##STR00007##
[0171] In the formula (7), X is, for example, a sulfo group
(including a sulfonate), a sulfonyl group, a carboxylic acid group
(including a carboxylate), an amino group, a phosphoric acid group
(including a phosphate and a phosphoric ester), a phosphino group,
an epoxy group, an isocyanate group, a thiol group, and the
like.
[0172] A compound having, in its molecule, a structure represented
by the formula (8) below can be used as the second compound having
an adsorption group.
##STR00008##
[0173] In the formula (8), X is, for example, a sulfo group
(including a sulfonate), a sulfonyl group, a carboxylic acid group
(including a carboxylate), an amino group, a phosphoric acid group
(including a phosphate and a phosphoric ester), a phosphino group,
an epoxy group, an isocyanate group, a thiol group, and the
like.
[0174] A compound having, in its molecule, a structure represented
by the formula (9) below can be used as the third compound having
an adsorption group.
##STR00009##
[0175] In the formula (9), X is, for example, a sulfo group
(including a sulfonate), a sulfonyl group, a carboxylic acid group
(including a carboxylate), an amino group, a phosphoric acid group
(including a phosphate and a phosphoric ester), a phosphino group,
an epoxy group, an isocyanate group, a thiol group, and the
like.
[Method of Producing Anti-Smudge Substrate]
[0176] A description will next be given of an example of a method
of producing the anti-smudge substrate using a wet process.
(Preparation of Processing Solution)
[0177] First, the adsorption compound 25a is dissolved in a solvent
to prepare a processing solution. When the adsorption compound 25a
is liquid at room temperature or is subjected to, for example, heat
treatment to obtain the adsorption compound 25a in a liquid state,
the adsorption compound 25a may be used as it is without dissolving
in a solvent. When the processing solution comes close to the
surface of the inner protrusions 24a, the adsorption compound 25a
is adsorbed on the surface. The adsorption rate increases as the
amount of the adsorption compound in the processing solution
increases. Therefore, the higher the concentration of the compound
is, the more it is preferred. Specifically, the concentration of
the compound is preferably 0.01% by mass or more.
[0178] The solvent used may be appropriately selected from those
that can dissolve the adsorption compound 25a at a prescribed
concentration. More specifically, the solvent used is, for example,
one or a mixture of two or more of: aromatic-based solvents such as
toluene and xylene; alcohol-based solvents such as methyl alcohol,
ethyl alcohol, n-propyl alcohol, iso-propyl alcohol, n-butyl
alcohol, iso-butyl alcohol, and propylene glycol monomethyl ether;
ester-based solvents such as methyl acetate, ethyl acetate, butyl
acetate, and cellosolve acetate; ketone-based solvents such as
acetone, methyl ethyl ketone, methyl isobutyl ketone, and
cyclohexanone; glycol ethers such as 2-methoxyethanol,
2-ethoxyethanol, 2-butoxyethanol, ethylene glycol dimethyl ether,
ethylene glycol diethyl ether, diethylene glycol dimethyl ether,
and propylene glycol methyl ether; glycol ether esters such as
2-methoxyethyl acetate, 2-ethoxyethyl acetate, 2-butoxyethyl
acetate, and propylene glycol methyl ether acetate; chlorine-based
solvents such as chloroform, dichloromethane, trichloromethane, and
methylene chloride; ether-based solvents such as tetrahydrofuran,
diethyl ether, 1,4-dioxane, and 1,3-dioxolane; N-methylpyrrolidone;
dimethylformamide; dimethyl sulfoxide; and dimethylacetamide.
(Adsorption)
[0179] Next, for example, the substrate 11, which is a processing
target, is immersed in the processing solution, or a prescribed
amount of the processing solution is applied to or printed on one
of or both the surfaces of the substrate 11 used as the processing
target.
[0180] The coating method used may be, for example, wire bar
coating, blade coating, spin coating, reverse roll coating, die
coating, spray coating, roll coating, gravure coating,
micro-gravure coating, lip coating, air knife coating, curtain
coating, a comma coating method, or a dipping method. The printing
method used may be, for example, a letterpress printing method, an
offset printing method, a gravure printing method, an intaglio
printing method, a rubber plate printing method, an inkjet method,
or a screen printing method.
[0181] When an immersion method is used, the processing solution in
an amount sufficient to allow the substrate 11 used as the
processing target to be immersed therein is prepared, and it is
preferable that the substrate 11 be immersed in the processing
solution for 0.1 seconds to 48 hours. If necessary, after
immersion, the substrate 11 may be washed with a good solvent for
the adsorption compound 25a to rinse out the unadsorbed adsorption
compound 25a. Then the resultant substrate 11 is dried as needed,
and the adsorption processing is thereby completed. The drying
method may be, for example, any of natural drying and artificial
drying using a heating apparatus. When heat treatment and/or
ultrasonic treatment is performed during immersion of the substrate
11 used as the processing target, the rate of adsorption of the
adsorption compound 25a can be increased.
[0182] When a coating method is used, heat treatment and/or
ultrasonic treatment may also be performed on the substrate 11 when
the processing solution is applied to the substrate 11. If
necessary, after application, the substrate 11 may be washed with a
good solvent for the adsorption compound 25a to rinse out the
unadsorbed adsorption compound 25a. Then the resultant substrate 11
is dried as needed, and the adsorption processing is thereby
completed. The drying method may be, for example, any of natural
drying and artificial drying using a heating apparatus. It is not
necessary to achieve the desired amount of application of the
processing solution only by one application step, and the desired
amount of application of the processing solution may be achieved by
repeating the above application and washing steps a plurality of
times.
(Effects)
[0183] In the fourth embodiment, the adsorption compound 25a is
adsorbed on the surface of the inner protrusions 24a to form the
anti-smudge layer 25 on the surface of the inner protrusions 24a.
Therefore, the same effects as those in the first embodiment
described above can be obtained.
[Modification]
[0184] In the third and fourth embodiments described above, the
method using a wet process has been described as an example of the
method of producing the anti-smudge substrate. The method of
producing the anti-smudge substrate is not limited to this example,
and a dry process can also be used. More specifically, a dry
process can be used to form the anti-smudge layer 12 in the third
embodiment or the fourth embodiment described above directly on the
surface of the inner protrusions 24a.
[0185] The dry process used may be, for example, a sputtering
method, a thermal CVD (Chemical Vapor Deposition) method, a plasma
CVD method, an ALD (Atomic Layer Deposition) method, an ion plating
method, etc.
5. Fifth Embodiment
[0186] FIG. 13 is a perspective view illustrating an example of a
configuration of a display device according to a fifth embodiment
of the present technique. As shown in FIG. 13, an anti-smudge body
100 is provided on a display surface S.sub.1 of the display device
101. Examples of the anti-smudge body 100 used may include an
anti-smudge layer, an anti-smudge structure layer, and an
anti-smudge substrate. Examples of the anti-smudge layer used may
include the anti-smudge layer 12 according to the first embodiment.
Examples of the anti-smudge structure layer used may include the
anti-smudge structure layer 23 according to the third or fourth
embodiment. Examples of the anti-smudge substrate used may include
the anti-smudge substrates according to the first to the fourth
embodiments. When the anti-smudge substrate is used as an
anti-smudge body, a configuration in which the anti-smudge
substrate is bonded to the display surface S.sub.1 of the display
device 101 through a bonding layer can be used. When this
configuration is used, it is preferable to use, for example, a
transparent and flexible sheet as the substrate 11 of the
anti-smudge substrate.
[0187] The display device 101 used may be any of various display
devices such as a liquid crystal display, a CRT (Cathode Ray Tube)
display, a plasma display (Plasma Display Panel: PDP), an electro
luminescent (Electro Luminescence: EL) display, and a
surface-conduction electron-emitter display (Surface-conduction
Electron-emitter Display: SED).
[Effects]
[0188] In the fifth embodiment, since the display surface S.sub.1
of the display device 101 can serve as the fingerprint resistant
surface S, fingerprints etc. adhering to the display surface
S.sub.1 of the display device 101 can be made less noticeable by
allowing the fingerprint patterns to spontaneously spread.
Therefore, the visibility of the display device 101 can be
improved.
[0189] When the average height Hm of the protrusions 12a is 100 nm
or smaller, fingerprints adhering to the display surface S.sub.1 of
the display device 101 can be made less noticeable by rubbing the
fingerprints with, for example, a finger to spread them thinly.
Therefore, the visibility of the display device 101 can be further
improved.
6. Sixth Embodiment
[0190] FIG. 14A is a perspective view illustrating an example of a
configuration of a display device according to a sixth embodiment
of the present technique. As shown in FIG. 14A, an input device 102
is disposed on the display surface S.sub.1 of the display device
101. An anti-smudge body 100 is disposed on an input surface
S.sub.2 of the input device 102. The display device 101 and the
input device 102 are bonded to each other through a bonding layer
formed of, for example, an adhesive. Examples of the anti-smudge
body 100 used may include an anti-smudge layer, an anti-smudge
structure layer, and an anti-smudge substrate. Examples of the
anti-smudge layer used may include the anti-smudge layer 12
according to the first embodiment. Examples of the anti-smudge
structure layer used may include the anti-smudge structure layer 23
according to the third or fourth embodiment. Examples of the
anti-smudge substrate used may include the anti-smudge substrates
according to any of the first to the fourth embodiments. When the
anti-smudge substrate is used as an anti-smudge body, a
configuration in which the anti-smudge substrate is bonded to the
input surface S.sub.2 of the input device 102 through a bonding
layer can be used. When this configuration is used, it is
preferable to use, for example, a transparent and flexible sheet as
the substrate 11 of the anti-smudge substrate.
[0191] The input device 102 can employ, for example, a resistive
film type or capacitive type touch panel, but is not limited
thereto. Examples of the resistive film type touch panel may
include a matrix resistive film type touch panel. Examples of the
capacitive type touch panel may include a projection capacitive
type touch panel of the Wire Sensor mode and a projection
capacitive type touch panel of the ITO Grid mode.
[Effects]
[0192] In the sixth embodiment, the input surface S.sub.2 of the
input device 102 can serve as the fingerprint resistant surface S,
so that fingerprints etc. adhering to the input surface S.sub.2 of
the input device 102 can be made less noticeable by allowing the
fingerprint patterns to spontaneously spread. Therefore, the
visibility of the display device 101 equipped with the input device
102 can be improved.
[0193] When the average height Hm of the protrusions 12a is 100 nm
or smaller, fingerprints adhering to the input surface S.sub.2 of
the input device 102 can be made less noticeable by rubbing the
fingerprints with, for example, a finger to spread them thinly.
Therefore, the visibility of the display device 101 provided with
the input device 102 can be further improved.
[Modification]
[0194] FIG. 14B is an exploded perspective view illustrating an
example of a configuration of a modification of the input device
according to the sixth embodiment of the present technique. As
shown in FIG. 14B, a front panel (surface member) 103 may be
provided on the input surface S.sub.2 of the input device 102. In
this case, an anti-smudge body 100 is provided on a panel surface
S.sub.3 of the front panel 103. The input device 102 and the front
panel (surface member) 103 are bonded to each other through a
bonding layer formed of, for example, an adhesive.
7. Seventh Embodiment
[0195] An electronic device according to a seventh embodiment of
the present technique includes a display device 101 according to
the fifth embodiment, the sixth embodiment, or its modification. If
necessary, an anti-smudge body is provided on the surface of the
casing of this electronic device. Examples of the anti-smudge body
used may include an anti-smudge layer, an anti-smudge structure
layer, and an anti-smudge substrate. Examples of the anti-smudge
layer used may include the anti-smudge layer 12 according to the
first embodiment. Examples of the anti-smudge structure layer used
may include the anti-smudge structure layer 23 according to the
third or fourth embodiment. Examples of the anti-smudge substrate
used may include the anti-smudge substrates according to the first
to the fourth embodiments. The anti-smudge substrate itself may
form the casing of the electronic device.
[0196] An example of the electronic device according to the seventh
embodiment of the present technique will next be described.
[0197] FIG. 15A is an external view illustrating a television set,
which is an example of the electronic device. The television set
111 includes a casing 112 and a display device 113 contained in the
casing 112. The display device 113 is a display device 101
according to the fifth embodiment, the sixth embodiment, or its
modification. If necessary, an anti-smudge body may be provided on
the surface of the casing 112, or the casing 112 itself may be
formed from an anti-smudge substrate.
[0198] FIG. 15B is an external view illustrating a notebook-type
personal computer, which is an example of the electronic device.
The notebook-type personal computer 121 includes a computer main
body 122 and a display device 125. The computer main body 122 and
the display device 125 are contained in a casing 123 and a casing
124, respectively. The display device 125 is a display device 101
according to the fifth embodiment, the sixth embodiment, or its
modification. If necessary, an anti-smudge body may be provided on
the surfaces of the casing 123 and the casing 124, and the casing
123 and the casing 124 themselves may be formed from an anti-smudge
substrate.
[0199] FIG. 16A is an external view illustrating a cellular phone,
which is an example of the electronic device. The cellular phone
131 is a so-called smart phone, and includes a casing 132 and a
display device 133 contained in the casing 132. The display device
133 is a display device 101 according to the sixth embodiment, or
its modification. If necessary, an anti-smudge body may be provided
on the surface of the casing 132, or the casing 132 itself may be
formed from an anti-smudge substrate.
[0200] FIG. 16B is an external view illustrating a tablet-type
computer, which is an example of the electronic device. The
tablet-type computer 141 includes a casing 142 and a display device
143 contained in the casing 142. The display device 143 is a
display device 101 according to the sixth embodiment, or its
modification. If necessary, an anti-smudge body may be provided on
the surface of the casing 142, or the casing 142 itself may be
formed from an anti-smudge substrate.
[Effects]
[0201] In the seventh embodiment, the electronic device includes
the display device 101 according to the fifth embodiment, the sixth
embodiment, or its modification, so that the visibility of the
display device 101 of the electronic device can be improved. When
the average height Hm of the protrusions 12a is 100 nm or smaller,
the visibility of the display device 101 of the electronic device
can be further improved.
[0202] When an anti-smudge body is provided on the surface of the
casing of the electronic device, if fingerprints adhere to the
surface of the casing of the electronic device, the fingerprint
patterns spontaneously spread thinly and become less noticeable.
Therefore, smudges on the surface of the casing can be made less
noticeable. When the average height Hm of the protrusions 12a is
100 nm or smaller, fingerprints adhering to the surface of the
casing of the electronic device can be made less noticeable by
rubbing the fingerprints with, for example, a finger to spread them
thinly. Therefore, the smudges on the surface of the casing can be
made further less noticeable.
EXAMPLES
[0203] The present technique will next be specifically described by
way of Examples. However, the present technique is not limited only
to these Examples.
[0204] In the following Examples, the average arrangement pitch,
average height, and average aspect ratio of protrusions were
determined as follows.
[0205] First, a fingerprint resistant surface having protrusions
was observed under an atomic force microscope (AFM), and pitches
and heights of protrusions were determined from an AFM cross
sectional profile. This procedure was repeated for 10 regions
randomly selected on the fingerprint resistant surface to determine
arrangement pitches P1, P2, . . . , P10 and heights H1, H2, . . . ,
H10. The pitch of protrusions is the distance between the apexes of
the protrusions, and the heights of the protrusions are their
heights with reference to the lowest point in recessed portions
(valley portions) between the protrusions. Then the pitches and
heights were simply averaged (arithmetically averaged) to determine
the average arrangement pitch Pm and average height Hm of the
protrusions. Next, the average aspect ratio Hm/Pm was determined
from the determined average arrangement pitch Pm and average height
Hm.
Example 1
[0206] First, a glass master roll with an outer diameter of 126 mm
was prepared, and a resist layer was formed on the surface of the
glass master roll in the following manner. Specifically, a
photo-resist was diluted 1/10 with a thinner, and the columnar
surface of the glass master roll was coated with the diluted resist
to a thickness of about 70 nm by a dipping method to thereby form a
resist layer. Next, the glass master roll serving as a recording
medium was conveyed to the master roll exposure apparatus shown in
FIG. 3, and the resist layer was exposed to light to pattern the
resist layer such that latent images were arranged on one helix
with adjacent three tracks forming a hexagonal lattice pattern.
Specifically, a region in which a hexagonal lattice-like exposure
pattern was to be formed was irradiated with laser light to thereby
form the hexagonal lattice-like exposure pattern. The power of the
laser light was 0.50 mW/m, which allowed the surface of the glass
master roll to be exposed to the laser light.
[0207] Next, the resist layer on the glass master roll was
subjected to development treatment, i.e., portions of the resist
layer exposed to the light were dissolved to perform development.
Specifically, the undeveloped glass master roll was placed on a
turntable of an unillustrated development apparatus, and a
developer was dropped onto the surface of the glass master roll
while the turntable together with the glass master roll was rotated
to thereby develop the resist layer on the surface. In this manner,
a resist glass master in which openings arranged in a hexagonal
lattice pattern were formed on the resist layer was obtained.
[0208] Next, plasma etching was performed in a CHF.sub.3 gas
atmosphere using a roll etching apparatus. The etching proceeded
only in hexagonal lattice pattern regions exposed from the resist
layer on the surface of the glass master roll, and the other
regions were not etched because the resist layer served as a mask,
whereby elliptical cone-shaped recessed portions were formed in the
glass master roll. In this case, the amount (depth) of etching was
controlled by etching time. Finally, the resist layer was
completely removed by O.sub.2 asking, and a glass master roll with
a hexagonal lattice pattern of recessed portions was thereby
obtained. In this glass master roll, the depth of the recessed
portions in an inter-track direction was larger than the depth of
the recessed portions in the extending direction of the tracks.
[0209] Next, the master roll obtained as described above was used
to form a plurality of protrusions two-dimensionally on the surface
of a ZEONOR film (registered trademark, manufactured by Zeon
Corporation) by UV imprinting. Specifically, the master roll
obtained as described above was brought into close contact with the
ZEONOR film coated with an ultraviolet-curable resin composition
(hereinafter referred to as a "UV-curable resin") having the
following chemical composition, and the ZEONOR film was peeled off
while the UV-curable resin was cured by UV irradiation. An optical
film in which a plurality of protrusions (inner protrusions) with
the following configuration were arranged on its surface was
thereby obtained.
(Chemical Composition of UV-Curable Resin)
[0210] Polyester acrylate oligomer (product name: CN2302,
manufactured by Sartomer): 95% by mass
[0211] Photo-polymerization initiator (product name: IRGACURE-184,
manufactured by BASF Japan Ltd.: 5% by mass
(Configuration of Protrusions)
[0212] Arrangement of protrusions: Closest packed (hexagonal
lattice)
[0213] Shape of protrusions: Bell shape (substantially paraboloidal
shape)
[0214] Average arrangement pitch Pm of protrusions: 250 nm
[0215] Average height Hm of protrusions: 150 nm
[0216] Average aspect ratio (Hm/Pm) of protrusions: 0.6
[0217] Next, the obtained optical film was cut into a prescribed
size. Then a shape transfer surface of the cut optical film was
spin-coated with an anti-smudge ultraviolet-curable resin
composition (hereinafter referred to as a "UV curable anti-smudge
resin") having a chemical composition described below, and the UV
curable anti-smudge resin was dried to thereby form a coating
conforming to the plurality of protrusions on the surface of the
optical film. Next, the coating was cured by irradiation with
ultraviolet rays to form a plurality of protrusions (surface
protrusions) having a configuration described below on the surface
of the anti-smudge layer. The height and aspect ratio of the
protrusions were controlled by the conditions for spin coating with
the UV curable anti-smudge resin. The intended anti-smudge film was
thereby obtained. FIG. 17A shows an AFM image of the surface of the
anti-smudge film in Example 1. FIG. 17B shows a cross-sectional
profile along line a-a shown in FIG. 17A.
(Chemical Composition of UV Curable Anti-Smudge Resin)
[0218] Compound having a structure represented by the formula (10)
below: 3.5% by mass
[0219] Photo-polymerization initiator (product name: IRGACURE-184,
manufactured by BASF Japan Ltd.): 0.175% by mass
[0220] Cyclohexanone: 96.325% by mass
##STR00010##
(Configuration of Protrusions)
[0221] Arrangement of protrusions: Closest packed (hexagonal
lattice)
[0222] Shape of protrusions: Bell shape (substantially paraboloidal
shape)
[0223] Average arrangement pitch Pm of protrusions: 250 nm
[0224] Average height Hm of protrusions: 60 nm
[0225] Average aspect ratio (Hm/Pm) of protrusions: 0.24
[0226] The intended anti-smudge film was thereby obtained.
Example 2
[0227] An anti-smudge film was obtained in the same manner as in
Example 1 except that the conditions for spin coating with the UV
curable anti-smudge resin were adjusted to change the height of the
protrusions to 40 nm and their aspect ratio to 0.16. FIG. 18A shows
an AFM image of the surface of the anti-smudge film in Example 2.
FIG. 18B shows a cross-sectional profile along line a-a shown in
FIG. 18A.
Example 3
[0228] An anti-smudge film was obtained in the same manner as in
Example 1 except that an ultraviolet-curable resin composition
having the following chemical composition was used to form a
plurality of protrusions two-dimensionally on the surface of a
ZEONOR film.
(Chemical Composition of Resin Composition)
[0229] Urethane acrylate oligomer (product name: CN9006,
manufactured by Sartomer): 64% by mass
[0230] Polyester acrylate oligomer (product name: CN2302,
manufactured by Sartomer): 31% by mass
[0231] Photo-polymerization initiator (product name: IRGACURE-184,
manufactured by BASF Japan Ltd.): 5% by mass
Example 4
[0232] An anti-smudge film was obtained in the same manner as in
Example 1 except that a UV curable anti-smudge resin having the
following chemical composition was used.
(UV Curable Anti-Smudge Resin)
[0233] Compound having a structure represented by the formula (11)
below: 3.5% by mass
[0234] Photo-polymerization initiator (product name: IRGACURE-184,
manufactured by BASF Japan Ltd.): 0.175% by mass
[0235] Cyclohexanone: 96.325% by mass
##STR00011##
Example 5
[0236] An anti-smudge film was obtained in the same manner as in
Example 1 except that a UV curable anti-smudge resin having the
following chemical composition was used.
(UV Curable Anti-Smudge Resin)
[0237] Compound having a structure represented by the formula (12)
below: 3.5% by mass
[0238] Photo-polymerization initiator (product name: IRGACURE-184,
manufactured by BASF Japan Ltd.): 0.175% by mass
[0239] Cyclohexanone: 96.325% by mass
##STR00012##
Example 6
[0240] An anti-smudge film was obtained in the same manner as in
Example 1 except that a UV curable anti-smudge resin having the
following chemical composition was used.
(UV Curable Anti-Smudge Resin)
[0241] Compound having a structure represented by the formula (13)
below: 0.3% by mass
[0242] Urethane acrylate (product name: CN9006, manufactured by
Sartomer): 3.2% by mass
[0243] Photo-polymerization initiator (product name: IRGACURE-184,
manufactured by BASF Japan Ltd.): 0.175% by mass
[0244] Cyclohexanone: 96.325% by mass
##STR00013##
Example 7
[0245] An optical film with a plurality of protrusions formed on
its surface was obtained in the same manner as in Example 1. Next,
an anti-smudge film was obtained in the same manner as in Example 1
except that an anti-smudge thermosetting resin composition
(hereinafter referred to as a "thermosetting anti-smudge resin")
having the following chemical composition was applied to the shape
transfer surface of the optical film by spin coating and then
heated at 150.degree. C. for 2 hours to heat-cure the thermosetting
anti-smudge resin.
(chemical Composition of Thermosetting Anti-Smudge Resin)
[0246] Compound having a structure represented by the formula (14)
below: 3.5% by mass
[0247] Solvent (acetone): 96.5% by mass
##STR00014##
Example 8
[0248] A plurality of protrusions were formed two-dimensionally on
the surface of a ZEONOR film in the same manner as in Example 1
except that a UV curable anti-smudge resin having a chemical
composition described later was used instead of the UV-curable
resin, whereby an anti-smudge film was obtained. In this Example,
the plurality of protrusions themselves are formed from the UV
curable anti-smudge resin. Since the UV curable anti-smudge resin
is applied to the shape transfer surface of the optical film and
then cured, the step of forming an anti-smudge layer so as to
conform to the surface of the plurality of protrusions is omitted.
FIG. 19A shows an AFM image of the surface of the anti-smudge film
in Example 8. FIG. 19B shows a cross-sectional profile along line
a-a shown in FIG. 19A.
(Chemical Composition of UV Curable Anti-Smudge Resin)
[0249] Compound having a structure represented by the formula (10)
below: 95% by mass
[0250] Photo-polymerization initiator (product name: IRGACURE-184,
manufactured by BASF Japan Ltd.): 5% by mass
##STR00015##
(Configuration of Protrusions)
[0251] Arrangement of protrusions: Closest packed (hexagonal
lattice)
[0252] Shape of protrusions: Bell shape (substantially paraboloidal
shape)
[0253] Average arrangement pitch Pm of protrusions: 250 nm
[0254] Average height Hm of protrusions: 150 nm
[0255] Average aspect ratio (Hm/Pm) of protrusions: 0.6
Example 9
[0256] An anti-smudge film was obtained in the same manner as in
Example 1 except that an ultraviolet-curable resin having the
following chemical composition was used.
(UV Curable Anti-Smudge Resin)
[0257] Acrylate oligomer having a fluorine atom and a siloxane
site: 1.75% by mass
[0258] Dipentaerythritol hexaacrylate (DPHA): 1.75% by mass
[0259] Photo-polymerization initiator (product name: IRGACURE-184,
manufactured by BASF Japan Ltd.): 0.175% by mass
[0260] Cyclohexanone: 96.325% by mass
Comparative Example 1
[0261] An anti-smudge film was obtained in the same manner as in
Example 1 except that a plurality of protrusions were not formed on
the surface of a ZEONOR film and the UV curable anti-smudge resin
was applied to the flat surface of the ZEONOR film by spin
coating.
[Evaluation]
[0262] The fingerprint resistance (noticeability of fingerprint
patterns, wipeability with CLEAN WIPER, and wipeability with a
finger) of each of the above-obtained anti-smudge films in Examples
1 to 8 and Comparative Example 1 and their pencil hardness were
evaluated.
(Fingerprint Resistance)
[0263] First, an anti-smudge film was bonded to a black acrylic
plate (product name: ACRYLITE, manufactured by Mitsubishi Rayon
Co., Ltd.) with an evaluation surface (fingerprint resistant
surface) of the anti-smudge film facing up using a double-sided
adhesive sheet (product name: LUCTACS CS9621T, manufactured by
Nitto Denko Corporation). Next, the evaluation surface was smudged
with fingerprints, and (a) noticeability of fingerprint patterns,
(b) wipeability with CLEAN WIPER, and (c) wipeability with a finger
were evaluated according to the following criteria. The results are
shown in TABLE 1.
(a) Noticeability of Fingerprint Patterns
[0264] The fingerprint resistant surface was smudged with
fingerprints. After one minute, a fluorescent lamp was used to
irradiate the evaluation surface. Then the surface was visually
observed, and evaluation was made according to the following
criteria.
[0265] AA: The fingerprint patterns disappeared and became less
noticeable.
[0266] A: The fingerprint patterns disappeared, but the smudged
portions were noticeable.
[0267] C: The fingerprint patterns did not disappear.
(b) Wipeability with CLEAN WIPER
[0268] The fingerprint resistant surface was smudged intentionally
with fingerprints with a liquid amount larger than usual and wiped
with KURAFLEX CLEAN WIPER FF-390C such that the CLEAN WIPER was
moved so as to draw a circle 10 times. Then a fluorescent lamp was
used to irradiate the fingerprint resistant surface. Then the
surface was visually observed, and evaluation was made according to
the following criteria.
[0269] AA: No oily smudges remained.
[0270] A: A slight amount of oily smudges remained.
[0271] C: A large amount of oily smudges remained.
(c) Wipeability with Finger
[0272] The fingerprint resistant surface was smudged intentionally
with fingerprints with a liquid amount larger than usual and wiped
back and forth 10 times with a finger. Then a fluorescent lamp was
used to irradiate the fingerprint resistant surface. Then the
surface was visually observed, and evaluation was made according to
the following criteria.
[0273] AA: No oily smudges remained.
[0274] A: A slight amount of oily smudges remained.
[0275] C: A large amount of oily smudges remained.
(Pencil Hardness)
[0276] The pencil hardness was evaluated according to JIS K5600
5-4.
[0277] TABLE 1 shows the configuration of each of the anti-smudge
films in Examples 1 to 9 and Comparative Example 1 and the results
of the evaluation.
TABLE-US-00001 TABLE 1 Irregular Shape of Transferred Objects
Noticeability Wipeability Pm Hm of Fingerprint with Clean
Wipeability Pencil Material of Anti-Smudge Layer Structure (nm)
(nm) Asp. Patterns Wiper with Finger Hardness Example 1 Second
Compound Closest Packed 250 60 0.24 AA AA AA -- (Cyclic Hydrocarbon
Group) Example 2 Second Compound Closest Packed 250 40 0.16 AA AA
AA -- (Cyclic Hydrocarbon Group) Example 3 Second Compound Closest
Packed 250 60 0.24 AA AA AA 2H (Cyclic Hydrocarbon Group) Example 4
Second Compound Closest Packed 250 60 0.24 AA AA AA -- (Cyclic
Hydrocarbon Group) Example 5 First Compound Closest Packed 250 60
0.24 AA AA AA -- (Ester Linkage in Portion Other Than Terminal
Ends) Example 6 First Compound Closest Packed 250 60 0.24 AA AA AA
-- (Ester Linkage in Portion Other Than Terminal Ends) Example 7
Second Compound Closest Packed 250 60 0.24 AA AA AA -- (Cyclic
Hydrocarbon Group) Example 8 Second Compound Closest Packed 250 150
0.6 A C C -- (Cyclic Hydrocarbon Group) Example 9 First Compound
Closest Packed 250 60 0.24 AA AA AA -- (Ester Linkage in Portion
Other Than Terminal Ends) Comparative Second Compound -- -- -- -- C
A A -- Example 1 (Cyclic Hydrocarbon Group) Pm: Average Arrangement
Pitch of Protrusions Hm: Average Height of Protrusions Asp.:
Average Aspect Ratio of Protrusions (Hm/Pm)
[0278] The following can be seen from TABLE 1.
[0279] Example 1: Since the anti-smudge layer contains the second
compound having a cyclic hydrocarbon group and the plurality of
protrusions with an average height Hm of 60 nm are disposed on the
fingerprint resistant surface, noticeability of fingerprint
patterns can be reduced, and high wipeability can be obtained.
[0280] Example 2: Even when the average height Hm of the plurality
of protrusions on the fingerprint resistant surface is 40 nm,
noticeability of fingerprint patterns can be reduced, and high
wipeability can be obtained.
[0281] Example 3: By adjusting the chemical composition of the UV
curable resin composition, a hard coating function can be further
imparted to the fingerprint resistant surface, in addition to the
above-described effects in Examples 1 and 2.
[0282] Example 4: Although the anti-smudge layer contains a second
compound different from that in Example 1, the same effects as in
Example 1 are obtained.
[0283] Example 5: Since the anti-smudge layer contains a first
compound having an ester linkage in a portion other than its
terminal ends and a plurality of protrusions with an average height
Hm of 60 nm are disposed on the fingerprint resistant surface,
noticeability of fingerprint patterns can be reduced, and high
wipeability can be obtained, as in Example 1.
[0284] Example 6: Although the anti-smudge layer contains a first
compound different from that in Example 5, the same effects as in
Example 5 are obtained.
[0285] Example 7: Even when a thermosetting anti-smudge resin
containing a second compound is used, noticeability of fingerprint
patterns can be reduced, and high wipeability can be obtained, as
in the case where a UV curable anti-smudge resin containing the
second compound is used (Example 1).
[0286] Example 8: Since the plurality of protrusions contain the
second compound having a cyclic hydrocarbon group and the plurality
of protrusions with an average height Hm of 150 nm are disposed on
the fingerprint resistant surface, noticeability of fingerprint
patterns can be reduced, but wipeability deteriorates.
[0287] Example 9: Although the anti-smudge layer contains a first
compound different from that in Example 5, the same effects as in
Example 5 are obtained.
[0288] Comparative Example 1: No protrusions are provided on the
surface of the substrate, and the anti-smudge layer is provided
directly on the surface of the substrate. Although high wipeability
can be obtained, noticeability of fingerprint patterns cannot be
reduced.
[0289] In comprehensive consideration of the above, when the
anti-smudge layer contains at least one of the first compound and
the second compound and a plurality of protrusions are disposed on
the fingerprint resistant surface, noticeability of fingerprint
patterns can be reduced.
[0290] To reduce the noticeability of fingerprint patterns and to
obtain high wipeability, it is preferable that at least one of the
first compound and the second compound be contained in the
anti-smudge layer and a plurality of protrusions with an average
height Hm of 100 nm or smaller and preferably 60 nm or smaller be
provided on the fingerprint resistant surface.
[0291] The embodiments of the present technique have been
specifically described above. However, the present technique is not
limited to the above embodiments, and various modifications can be
made on the basis of the technical idea of the present
technique.
[0292] For example, the configurations, methods, processes, shapes,
materials, values, etc. described in the above embodiments are
merely examples, and configurations, methods, processes, shapes,
materials, values, etc. different from those described above may be
used as needed.
[0293] The configurations, methods, processes, shapes, materials,
values, etc. in the above embodiments may be mutually combined so
long as the combination does not depart from the gist of the
present technique.
[0294] In addition, the present technique may be configured as
follows. [0295] (1) An anti-smudge body having
[0296] a surface and a plurality of protrusions provided thereto,
wherein
[0297] the protrusions contain at least one of a first compound
having an ester linkage in a portion other than terminal ends and a
second compound having a cyclic hydrocarbon group. [0298] (2) The
anti-smudge body according to (1), wherein an average height of the
protrusions is in a range of 10 nm or larger and 150 nm or smaller,
and
[0299] an average pitch of the protrusions is in a range of 100 nm
or larger and 500 nm or smaller. [0300] (3) The anti-smudge body
according to (2), wherein the average height of the protrusions is
in a range of 10 nm or larger and 100 nm or smaller. [0301] (4) The
anti-smudge body according to any of (1) to (3), including
[0302] a substrate having a surface, and
[0303] an anti-smudge layer provided on the surface of the
substrate, wherein
[0304] the anti-smudge layer has a surface on which the plurality
of protrusions are disposed. [0305] (5) The anti-smudge body
according to (4), wherein
[0306] the anti-smudge layer contains at least one resin
composition of an energy ray-curable resin composition and a
thermosetting resin composition, and
[0307] the resin composition contains the at least one of the first
compound and the second compound. [0308] (6) The anti-smudge body
according to any of (1) to (5), wherein the first compound and the
second compound are each an additive. [0309] (7) The anti-smudge
body according to (6), wherein the additive is a leveling agent.
[0310] (8) The anti-smudge body according to any of (4) to (7),
wherein a plurality of protrusions are disposed on the surface of
the substrate, and
[0311] the anti-smudge layer is provided so as to conform to the
surface of the plurality of protrusions of the substrate. [0312]
(9) The anti-smudge body according to (8), wherein the at least one
of the first compound and the second compound is adsorbed onto the
surface of the plurality of protrusions of the substrate. [0313]
(10) The anti-smudge body according to (9), wherein the anti-smudge
layer is a monomolecular layer containing the at least one of the
first compound and the second compound. [0314] (11) The anti-smudge
body according to any of (1) to (3), wherein
[0315] the protrusions contain a thermoplastic resin composition,
and
[0316] the thermoplastic resin composition contains the at least
one of the first compound and the second compound. (12) The
anti-smudge body according to any of (1) to (11), wherein
[0317] the first compound is represented by the formula (1) or (2)
below, and
[0318] the second compound is represented by the formula (3) or (4)
below,
##STR00016##
wherein, in the formula (1), R.sub.1 is a group containing C, N, S,
O, Si, P, or Ti, and R.sub.2 is a group having 2 or more carbon
atoms,
##STR00017##
wherein, in the formula (2), R.sub.1 and R.sub.2 are each
independently a group containing C, N, S, O, Si, P, or Ti
##STR00018## [0319] (13) The anti-smudge body according to (12),
wherein R.sub.1 and R.sub.2 in the formulas (1) and (2) above are
each independently a hydrocarbon group, a sulfo group, a sulfonyl
group, a sulfonamide group, a carboxylic acid group, an amino
group, an amide group, a phosphoric acid group, a phosphino group,
a silanol group, an epoxy group, an isocyanate group, a cyano
group, a thiol group, or a hydroxyl group. [0320] (14) The
anti-smudge body according to any of (1) to (13), wherein the
anti-smudge layer further contains, together with the second
compound, a third compound having a chain hydrocarbon group at a
terminal end. [0321] (15) The anti-smudge body according to (14),
wherein the third compound is represented by the formula (5) or (6)
below
[0321] ##STR00019## [0322] (16) The anti-smudge body according to
any of (1) to (15), wherein the plurality of protrusions are
arranged two-dimensionally. [0323] (17) The anti-smudge body
according to any of (1) to (16), wherein a recessed portion between
the protrusions causes positive capillary pressure to act on a
liquid present on the surface. [0324] (18) An input device
having
[0325] an input surface and a plurality of protrusions provided
thereto, wherein
[0326] the protrusions contain at least one of a first compound
having an ester linkage in a portion other than terminal ends and a
second compound having a cyclic hydrocarbon group. [0327] (19) A
display device having
[0328] a display surface and a plurality of protrusions provided
thereto, wherein
[0329] the protrusions contain at least one of a first compound
having an ester linkage in a portion other than terminal ends and a
second compound having a cyclic hydrocarbon group. [0330] (20) An
electronic device having
[0331] a surface and a plurality of protrusions provided thereto,
wherein
[0332] the protrusions contain at least one of a first compound
having an ester linkage in a portion other than terminal ends and a
second compound having a cyclic hydrocarbon group. [0333] (21) An
anti-smudge article having
[0334] a surface and a plurality of protrusions provided thereto,
wherein
[0335] the protrusions contain at least one of a first compound
having an ester linkage in a portion other than terminal ends and a
second compound having a cyclic hydrocarbon group. [0336] (22) An
anti-smudge body having an anti-smudge surface and a plurality of
protrusions provided thereto.
REFERENCE SIGNS LIST
[0337] 11, 21 substrate
[0338] 12, 25 anti-smudge layer
[0339] 12a, 22 protrusion
[0340] 12b, 24b base layer
[0341] 13 anchor layer
[0342] 14 hard coating layer
[0343] 15 transparent conductive layer
[0344] 23 anti-smudge structure layer
[0345] 23a surface protrusion (first protrusion)
[0346] 24 fine structure layer
[0347] 24a inner protrusion (second protrusion)
[0348] 25a adsorption compound
[0349] 31 master roll
[0350] 32 structure body
[0351] 101, 113, 125, 133, 143 display device
[0352] 102 input device
[0353] 103 front panel
[0354] 111 television set
[0355] 112, 124, 132, 142 casing
[0356] 121 notebook-type personal computer
[0357] 131 cellular phone
[0358] 141 tablet-type computer
[0359] S fingerprint resistant surface (anti-smudge surface)
[0360] S.sub.1 display surface
[0361] S.sub.2 input surface
* * * * *